Screening for Coronary Heart Disease: Recommendation Statement Guidelines for the Management of Patients with Chronic Stable Angina: Diagnosis and Risk Stratification Heart Rate Recovery after Submaximal Exercise Testing as a Predictor of Mortality in a Cardiovascularly Healthy Cohort Prognostic value of ECG findings for total, cardiovascular disease, and coronary heart disease death in men and women Electrocardiographic Minnesota code findings predicting short-term mortality in asymptomatic subjects. The Italian RIFLE Pooling Project (Risk Factors and Life Expectancy). Maximal exercise test as a predictor of risk for mortality from coronary heart disease in asymptomatic men. Global risk scores and exercise testing for predicting all-cause mortality in a preventive medicine program. Screening for Type 2 Diabetes Mellitus in Adults: Recommendations and Rationale Diagnostic and prognostic value of dipyridamole echocardiography in patients with suspected coronary artery disease. Comparison with exercise electrocardiography. Electrocardiographic findings and incident coronary heart disease among participants in the Atherosclerosis Risk in Communities (ARIC) study. Scintigraphic and electrocardiographic evidence of silent coronary artery disease in asymptomatic hypertension: a case-control study. Screening for Asymptomatic Bacteriuria in Adults: Updated Evidence Report and Systematic Review for the US Preventive Services Task Force. Coronary heart disease and all-causes mortality in the Multiple Risk Factor Intervention Trial: subgroup findings and comparisons with other trials. Prediction of cardiovascular death by means of clinical and exercise test variables in patients selected for cardiac catheterization. Comparative Effectiveness of Exercise Electrocardiography With or Without Myocardial Perfusion Single Photon Emission Computed Tomography in Women With Suspected Coronary Artery Disease: Results From the What Is the Optimal Method for Ischemia Evaluation in Women (WOMEN) Trial Asymptomatic myocardial ischaemia in HIV-infected adults Major and minor ECG abnormalities in asymptomatic women and risk of cardiovascular events and mortality. Statins for Primary Prevention: The Debate Is Intense, but the Data Are Weak. Screening for Lung Cancer: U.S. Preventive Services Task Force Recommendation Statement Detecting Occult Coronary Disease in a High-Risk Asymptomatic Population Preventive health care, 1999 update: prevention of oral cancer mortality. The Canadian Task Force on Preventive Health Care. Heart rate recovery and treadmill exercise score as predictors of mortality in patients referred for exercise ECG. Results of exercise testing at a mean age of 10 years after neonatal arterial switch operation Screening for cancer: advice for high-value care from the American College of Physicians. Update on the Methods of the U.S. Preventive Services Task Force: Estimating Certainty and Magnitude of Net Benefit Low risk-factor profile and long-term cardiovascular and noncardiovascular mortality and life expectancy: findings for 5 large cohorts of young adult and middle-aged men and women. Screening for Postmenopausal Osteoporosis: A Review of the Evidence for the U.S. Preventive Services Task Force Screening for Abdominal Aortic Aneurysm: US Preventive Services Task Force Recommendation Statement. Clinical value of attenuation correction in stress-only Tc-99m sestamibi SPECT imaging Morphological abnormalities in baseline ECGs in healthy normal volunteers participating in phase I studies Cardiovascular Safety of Transdermal Nicotine Patches in Patients with Coronary Artery Disease who Try to Quit Smoking
Summary of the Recommendations The U.S. Preventive Services Task Force ( USPSTF ) recommends against routine screening with resting electrocardiography ( ECG ) , exercise treadmill test ( ETT ) , or electron-beam computerized tomography ( EBCT ) scanning for coronary calcium for either the presence of severe coronary artery stenosis ( CAS ) or the prediction of coronary heart disease ( CHD ) events in adults at low risk for CHD events . This is a grade D recommendation . ( See Appendix Table 1 for a description of the USPSTF classification of recommendations . ) The USPSTF found at least fair evidence that ECG or ETT can detect some asymptomatic adults at increased risk for CHD events independent of conventional CHD risk factors ( see Clinical Considerations ) and that ETT can detect severe CAS in a small number of asymptomatic adults . Similar evidence for EBCT is limited . In the absence of evidence that such detection by ECG , ETT , or EBCT among adults at low risk for CHD events ultimately results in improved health outcomes , and because false-positive tests are likely to cause harm , including unnecessary invasive procedures , overtreatment , and labeling , the USPSTF concluded that the potential harms of routine screening for CHD in this population exceed the potential benefits . ( See Appendix Table 2 for a description of the USPSTF classification of levels of evidence . ) Appendix Table 1 . U.S. Preventive Services Task Force Grade s and Recommendations Appendix Table 2 . U.S. Preventive Services Task Force Strength of Overall Evidence The USPSTF found insufficient evidence to recommend for or against routine screening with ECG , ETT , or EBCT scanning for coronary calcium for either the presence of severe CAS or the prediction of CHD events in adults at increased risk for CHD events . This is a grade I recommendation . The USPSTF found inadequate evidence to determine the extent to which the added detection offered by ECG , ETT , or EBCT ( beyond that obtained by ascertainment of conventional CHD risk factors ) ( see Clinical Considerations ) would result in interventions that lead to improved CHD-related health outcomes among adults at increased risk for CHD events . Although there is limited evidence to determine the magnitude of harms from screening this population , harms from false-positive tests ( that is , unnecessary invasive procedures , overtreatment , and labeling ) are likely to occur . As a result , the USPSTF could not determine the balance between benefits and harms of screening this population for CHD . Clinical Considerations Several factors are associated with a higher risk for CHD events ( the major ones are nonfatal myocardial infa rct ion and coronary death ) , including older age , male gender , high blood pressure , smoking , abnormal lipid levels , diabetes , obesity , and sedentary lifestyle . A person 's risk for CHD events can be estimated on the basis of the presence of these factors . Calculators are available to ascertain a person 's risk for a CHD event ; for example , a calculator to estimate a person 's risk for a CHD event in the next 10 years can be accessed at hin.nhlbi.nih.gov/atpiii/calculator.asp?usertype=prof . Although the exact risk factors that constitute each of these categories ( low or increased risk ) have not been established , younger adults ( that is , men<50 years of age and women<60 years of age ) who have no other risk factors for CHD ( < 5 % to 10 % 10-year risk ) are considered to be at low risk . Older adults , or younger adults with one or more risk factors ( > 15 % to 20 % 10-year risk ) , are considered to be at increased risk . Screening with ECG , ETT , and EBCT could potentially reduce CHD events in 2 ways : either by detecting people at high risk for CHD events who could benefit from more aggressive risk factor modification or by detecting people with existing severe CAS whose life could be prolonged by coronary artery bypass grafting ( CABG ) surgery . However , the evidence is inadequate to determine the extent to which people detected through screening in either situation would benefit from either type of intervention . The consequences of false-positive tests may potentially outweigh the benefits of screening . False-positive tests are common among asymptomatic adults , especially women , and may lead to unnecessary diagnostic testing , overtreatment , and labeling . Because the sensitivity of these tests is limited , screening could also result in false-negative results . A negative test does not rule out the presence of severe CAS or a future CHD event . For people in certain occupations , such as pilots and heavy equipment operators ( for whom sudden incapacitation or sudden death may endanger the safety of others ) , considerations other than the health benefit to the individual patient may influence the decision to screen for CHD . Although some exercise programs initially screen asymptomatic participants with ETT , there is not enough evidence to determine the balance of benefits and harms of this practice . Discussion Coronary heart disease is the leading cause of death in the United States ; more than 700000 of the deaths in 2000 were due to heart disease ( 1 ) . The overall costs of CHD and stroke in 2003 are estimated to be greater than $ 350 billion ( 2 ) . Many clinicians ascertain a person 's overall risk for CHD events by screening for cardiac risk factors and incorporating that information into risk prediction equations derived from the Framingham or other cohort studies ( 3 , 4 ) . Asymptomatic adults clearly benefit from risk factor modification proportional to their degree of CHD risk ( that is , more intensive risk factor modification for people at higher risk ) ( 5 ) . Since those at high risk for CHD may already be receiving interventions to maximally reduce their risk for CHD events , screening may potentially be of greatest benefit to those presumed to be at intermediate risk for CHD who could be reclassified as being at high risk ( and thus treated more aggressively ) after additional testing . In addition to risk factor reduction , persons with symptoms of CHD who have severe CAS ( defined as either triple-vessel or left main coronary artery atherosclerotic disease with poor left ventricular function ) clearly benefit from CABG or percutaneous transluminal coronary angioplasty ( 6 - 8 ) . Among the asymptomatic population , those at higher risk for CHD events have a higher prevalence of severe CAS ; thus , the yield of screening is expected to be greater in this population . However , it is uncertain whether this increased yield increases the detection of people with severe CAS to an important degree and whether invasive revascularization procedures would benefit those who are asymptomatic as much as those who have symptoms of CAS . The USPSTF review ed the evidence as to whether supplementing the conventional CHD risk ascertainment strategy with additional screening using ECG , ETT , or EBCT , or using these 3 tests to identify people with severe CAS earlier , would lead to improved health outcomes in asymptomatic persons . The USPSTF found no r and omized , controlled trials with health outcomes that examined the extent to which  ECG , ETT , or EBCT scanning for coronary calcium provided additional prognostic information beyond the currently used risk factor calculations . The Task Force further found that the 3 screening testsECG , ETT , and EBCThave poor to fair accuracy in predicting CHD events . Systematic review s have reported that the sensitivity of resting ECG abnormalities for CHD events is low ( 3 , 9 ) . The prevalence of the most common ECG abnormalities ( Q waves , left ventricular hypertrophy , bundle-branch blocks , and ST-segment depression ) ranges from 1 % to 10 % ( 3 ) . Only a few studies have examined ECG abnormalities in the black population . Although major ECG abnormalities may be more prevalent in black men than in white men , these abnormalities may not confer the same risk for CHD death in black men ( relative risk , 1.95 [ 95 % CI , 0.93 to 4.11 ] ) as in white men ( relative risk , 2.72 [ CI , 1.47 to 5.04 ] ) ( 10 ) . The sensitivity of ETT  for the prediction of CHD events 3 to 12 years in the future ranges from 40 % to 62 % ; the positive predictive value ( PPV ) ranges from 6 % to 48 % . The higher sensitivity of ETT  reported in older studies may not be accurate because of the possibility of spectrum bias ( 11 , 12 ) . The prevalence of an abnormal ETT ( ST-segment depression 1 mm ) reportedly ranges from 5 % to 25 % ( 3 ) . The yield of ETT  in detecting severe CAS in asymptomatic middle-aged men is estimated to be 0.5 % ( 3 , 13 ) . The PPV for future CHD in recent cohort studies ( most of them conducted with asymptomatic men ) is low ( range , 6 % to 48 % ) ( 3 ) . Adding nuclear perfusion to ECG analysis may increase sensitivity somewhat ; however , the low PPV of ETT is due mainly to the low prevalence of CHD in asymptomatic persons and can not be corrected simply by improving test accuracy . For patients with symptoms of CHD , EBCT has a sensitivity of 80 % and a specificity of 40 % for detecting angiographically demonstrated CAS ( 14 ) ; similar data for those who have no symptoms are lacking . A systematic review reported that higher calcium scores on EBCT were associated with higher risk for CHD events ( 3 ) . This review concluded that EBCT may have a role in better defining risk for CHD events in those who have been identified as being at intermediate risk based on traditional risk factors , but no study has examined the effect of EBCT data on clinical decision making ( 3 ) . Potential harms of screening asymptomatic patients for CHD include unnecessary invasive testing ( for example , coronary angiography ) and labeling of those who have had false-positive test results . In low-risk asymptomatic population s , most positive ECG test results occur in those who will not have a CHD event in the next 5 to 10 years ( 3 ) . One study reported that 71 % of those without symptoms who had an abnormal ETT had no angiographically demonstrable CAS ( 15 ) . While the yield of screening is low in those at low risk for CHD , the potential for This article is the first of two papers about the care of patients with chronic stable angina . The second paper , which deals with the treatment of patients with chronic stable angina , will be published in a future issue . Both articles have been adapted from material s created by the Committee on Guidelines for Chronic Stable Angina sponsored by the American College of Cardiology ( ACC ) , the American Heart Association ( AHA ) , and the American College of PhysiciansAmerican Society of Internal Medicine ( ACPASIM ) ( 1 - 3 ) . The adaptations in these articles are intended to make the information more useful for clinicians who do not specialize in the care of patients with heart disease . The committee created the original material s after review ing published reports identified in part through MEDLINE search es of the English literature from 1975 through 1998 . The weight of the evidence was ranked high and given a grade of A if the data were derived from multiple r and omized clinical trials involving many patients . The weight of the evidence was ranked intermediate and given a grade of B if the data were derived from a few r and omized trials involving small numbers of patients , nonr and omized studies , or observational registries . A lower rank and a grade of C were given when an expert consensus was the primary basis for the recommendation . We used the following classification system for final recommendations . Class I referred to conditions for which there is evidence or general agreement that a given procedure or treatment is useful and effective ; class II referred to conditions for which there is conflicting evidence or a divergence of opinion about the usefulness or efficacy of a procedure or treatment ; class IIa referred to conditions for which the weight of evidence or opinion is in favor of usefulness or efficacy of a procedure or treatment ; class IIb referred to conditions for which usefulness or efficacy of a procedure or treatment is less well established by evidence or opinion ; and class III referred to conditions for which there is evidence or general agreement that the procedure or treatment is not useful or effective and in some cases may be harmful . For the sake of brevity , we have combined some original recommendations and omitted others , especially those that affect fewer patients , are based on weaker evidence , or recommend that interventions not be done . Scope of the Guidelines These recommendations are intended for adult patients with stable chest pain syndromes and known or suspected ischemic heart disease and patients who have ischemic equivalents , such as dyspnea or arm pain with exertion . Also , some recommendations about follow-up apply to patients who become asymptomatic during therapy . These guidelines are not intended for patients with acute ischemic syndromes , patients with chest pain after cardiac transplantation , patients with chest pain within 6 months of revascularization by percutaneous techniques or coronary artery bypass grafting ( CABG ) , patients with coronary artery disease ( CAD ) detected without symptoms , patients with nonanginal chest pain , or pediatric patients . The Initial Evaluation The initial evaluation of patients presenting with chest pain includes a detailed history , a focused physical examination , and performance of a few tests and procedures that are useful for estimating the probability of significant CAD ( Figure 1 ) . Significant CAD is defined as an obstruction of at least one major epicardial artery that occupies at least 70 % of the artery 's cross-sectional diameter or an obstruction of the left main coronary artery that occupies at least 50 % of its diameter . Figure 1 . Diagnosis of chest pain . Comorbid conditions and patient preferences . The history should elicit specific information about chest pain because accurate characterization helps determine whether CAD is the cause of angina . Angina usually occurs in patients with CAD , but it can occur in patients with unobstructed coronary arteries who have myocardial ischemia related to an arterial spasm or endothelial dysfunction . It also can occur in patients with other cardiovascular problems , such as aortic stenosis , hypertrophic cardiomyopathy , or uncontrolled hypertension . Symptoms that mimic angina can also occur in patients with noncardiac conditions involving the chest wall , esophagus , or lung . The following characteristics of chest pain should be determined : quality , location , duration , and the presence of factors that provoke and relieve the pain . Angina is characterized by a substernal pain or discomfort , although it may radiate to the neck , jaw , epigastrium , or arms . Patients often describe the quality of angina with characteristic terms , such as squeezing , grip-like , pressure-like , suffocating , or heavy . Angina usually lasts for minutes . Exertion or emotional stress provokes it , and rest or nitroglycerin relieves it , typically within 30 seconds to several minutes . After the history is obtained , the clinician should classify the chest pain . Typical angina has the following characteristics : 1 ) substernal chest discomfort with a characteristic quality and duration that is 2 ) provoked by exertion or emotional stress and 3 ) relieved by rest or nitroglycerin . Atypical angina has two of the three characteristics of typical angina , while noncardiac chest pain has one or none of the characteristics of typical angina . The term noncardiac chest pain means that the probability of CAD is low . The term nonspecific chest pain more accurately describes this situation , but tradition prevents its use . In patients with angina , the severity of pain should be grade d according to the Canadian Cardiovascular Society ( CCS ) classification system ( Table 1 ) ( 6 ) . Although grading chest pain is less useful for establishing a diagnosis or estimating risk , it is essential for evaluating the effects of therapy . Table 1 . Grading of Angina by the Canadian Cardiovascular Society Classification System In patients with angina , the stability of pain should be assessed . Patients have unstable angina if the pain started recently ; is more easily provoked ; or occurs with increased frequency , severity , or duration ( 7 ) . Some patients with unstable angina have a measurable risk for short-term death ( 8) . Those characterized as high risk have a 1.7 % probability of dying within 30 days , and those characterized as moderate risk have a 1.2 % probability . These patients have  pain at rest , nocturnal pain , signs or symptoms of heart failure , or new or ischemic changes on resting electrocardiography  ( ECG ) . They should be evaluated in the inpatient setting . However , patients with unstable angina whose pain has been present for at least 2 weeks and who lack any of angina 's more worrisome clinical features , including ECG changes , can be evaluated in an outpatient setting because their probability of death or myocardial infa rct ion within 30 days is indistinguishable from zero . The initial history should also include information about the risk factors for CAD , such as smoking , hyperlipidemia , diabetes , hypertension , and a family history of premature CAD . Findings on physical examination are often normal in patients with stable angina ( 9 ) . During an episode of pain , however , there uncommonly may be an S4 or S3 gallop , a mitral regurgitant murmur , a paradoxically split S2 , bibasilar rales , or a chest wall heave . Each of these findings makes CAD more likely , especially if the finding disappears when the pain goes away ( 10 ) . Evidence of noncoronary atherosclerotic disease , such as a carotid bruit , diminished pedal pulses , or an abdominal aneurysm , increases the likelihood of CAD . Elevated blood pressure , xanthomas , and retinal exu date s identify CAD risk factors . Table 2 lists recommendations for the tests and procedures that we believe should be used in the initial evaluation of patients with suspected chronic stable angina .  Resting , 12-lead ECG should be performed , although the results will be normal in 50 % of patients with chronic stable angina ( 11 ) . Therefore , results on normal resting ECG do not exclude CAD . Evidence on ECG of left ventricular hypertrophy or ST T-wave changes consistent with myocardial ischemia favor the diagnosis of angina ( 12 ) . The presence of arrhythmias , such as atrial fibrillation or ventricular tachyarrhythmias , also increases the probability of CAD , but other types of cardiac disease frequently cause these arrhythmias . Q waves suggesting a previous myocardial infa rct ion make CAD very likely , although an isolated Q wave in lead III or a QS pattern in lead V1 and V2 is often nonspecific . Atrioventricular block may suggest multivessel CAD but is also nonspecific . Table 2 . Recommendations for Initial Laboratory Tests , Electrocardiography , and Chest Radiography for the Diagnosis of Chronic Stable Angina Results on ECG performed during chest pain are abnormal in approximately 50 % of patients with angina who have normal results on resting ECG .  Sinus tachycardia occurs commonly ; bradyarrhythmias are less common . ST T-wave depression or inversion on resting ECG or pseudo-normalization of these abnormalities during pain is another indicator of CAD ( 13 ) . Tachyarrhythmias , atrioventricular blocks , left anterior fascicular block , or bundle-branch block occurring with chest pain also increases the probability of coronary heart disease . ST-segment elevation or depression also increases the probability of CAD , and it increases the risk for myocardial infa rct ion or death because there is ischemia at a low workload . Results of  chest radiography  are often normal in patients with stable angina , and its usefulness as a routine test is not well established . Ultra-fast electron-beam computed tomography is now frequently used to detect coronary artery calcification , which is a sensitive indicator of coronary stenosis ( 14 ) . However , the specificity of electron-beam computed tomography is in the range of 41 % to 76 % , which means that many results are false positive . Moreover , the We previously reported on the prognostic importance of heart rate recovery after symptom-limited exercise in an intermediate-risk group of patients who were referred for exercise testing with thallium single-photon emission computed tomography in a tertiary-care center ( 1 ) . It is unknown , however , whether these findings can be generalized to healthy adults undergoing submaximal exercise .  Our goal was to examine heart rate recovery as a predictor of long-term mortality in a population -based cohort of adults without evidence of cardiovascular disease who underwent submaximal exercise testing .  All-cause mortality was the outcome of interest because of its relevance and its objective and unbiased nature ( 2 ) . Methods The study cohort was derived from the Lipid Research Clinics Prevalence Study , the selection of which has been described in detail elsewhere ( 3 - 6 ) . Briefly , that study was design ed to determine the prevalence of lipid abnormalities among North Americans . Of the 68 317 population -based persons recruited from 10 primary care centers , those with lipid abnormalities ( approximately 10 % of the population ) and an additional r and omly selected 15 % were invited to undergo more extensive investigation ( 3 ) . Of the 13 852 who appeared for this second visit , 8681 underwent exercise testing .  Reasons for exclusion from exercise testing included  resting systolic blood pressure less than 90 or greater than 200 mm Hg , resting diastolic blood pressure greater than 120 mm Hg , inability to complete a treadmill test on the basis of physician examination , or participant request ( 5 , 6 ) . To assure selection of a cardiovascularly healthy asymptomatic cohort similar to that in previous population -based studies ( 7 ) , persons were excluded if they were younger than 30 years of age ( n=131 [ 2 % ] ) ; were taking -blockers , digoxin , antiarrhythmic agents , or nitrates ( n=356 [ 4 % ] ) ; had a history of cardiovascular disease ( defined as previous heart surgery or history of angina , myocardial infa rct ion , claudication , stroke , previous vascular surgery , congenital disease , or arrhythmia ) ( n=2413 [ 28 % ] ) ; or were unable to reach stage 2 of exercise ( n=1620 [ 19 % ] ) . Before testing , participants underwent a detailed medical and family history that elicited information about medical conditions , alcohol use , smoking , education level , socioeconomic status , exercise habits , and medications . Lipid profiles were obtained in all patients . The treadmill exercise protocol used was the Bruce or modified Bruce protocol ( 5 , 6 ) . Participants exercised until they attained at least 85 % to 90 % of their age- and fitness-predicted maximum heart rate for 1 minute or until fatigue or medical contraindications to continued exercise were observed . Data on symptoms , heart rate , and blood pressure were collected and  electrocardiography  was done before exercise , at the end of each stage , immediately after exercise , and 2 minutes into recovery . Estimated workload , expressed in metabolic equivalents , was based on total treadmill time . Chronotropic response during exercise was assessed by using the chronotropic indexthe ratio of heart rate to metabolic reserve usedduring stage 2 of exercise ( 8 , 9 ) . We used a cutoff value ( 0.86 ) that maximized the log-rank chi-square statistic ( 10 ) . Immediately after exercise , participants were helped to chairs , and recovery data were obtained . Heart rate recovery was defined as the change from peak heart rate to that measured after 2 minutes of recovery ( that is , heart rate recovery = heart ratepeak heart rate2-min recovery ) . An abnormal value for heart rate recovery was determined by finding the maximum value for the log-rank chi-square test statistic for all possible cutoff points between the 10th and 90th percentiles ( 10 ) ; this turned out to be 42 beats/min or less . This cutoff value differed from and could not be validly compared to that of our previous study ( 1 ) because 2-minute values ( rather than 1-minute values ) were used and because exercise was submaximal , not symptom-limited . We also considered indexing the 2-minute heart rate recovery by the maximum heart rate , but this result ed in a substantially lower maximum log-rank chi-square value ( 44 compared with 77 ) . Mean follow-up time was 12 years . The primary end point was all-cause mortality , which was determined through annual telephone interviews with study participants or their families or employers . Cause of death was assessed by review of death certificates and interviews of physicians or next of kin ( 6 ) . If the patient could not be contacted , registries were search ed for mortality information . For assessment of vital status , follow-up was 100 % complete . All analyses were performed by using version 6.12 of the SAS statistical package ( SAS Institute , Inc. , Cary , North Carolina ) . For descriptive purpose s , patients were divided into two groups based on heart rate recovery . Continuous variables are presented as the mean SD . Differences between groups were compared by using the Student t-test , Wilcoxon rank-sum test , and chi-square test , as appropriate . Heart rate recovery was related to all-cause mortality  by using univariable and multivariable Cox regression analyses . Stratified analyses were performed on prespecified subgroups according to age , sex , exercise patterns , smoking , cholesterol level , resting blood pressure and heart rate , chronotropic response to exercise , and medication use . Logarithmic and quadratic transformations and potential interactions were assessed for improvement of fit ; the strata option of PROC PHREG was used to allow for accurate estimation of main effects relative risks . The Cox proportional-hazards assumption was confirmed by inspection of log ( log [ survival ] ) curves . Attributable risk was calculated as P ( RR 1)/[P ( RR 1 ) + 1 ] , where P is prevalence and RR is relative risk . The estimated actuarial survival rate for the population was estimated on the basis of data from 1985 U.S. life tables ( 11 ) . According to the policy at our institution , this research was considered exempt from institutional review board approval because it used existing , publically available data . In addition , the data were recorded in such a manner that participants could not be identified directly or through identifiers linked to them . Results Baseline and Exercise Characteristics A total of 5234 adults met all inclusion criteria . The median value for heart rate recovery was 49 beats/min ( 25th and 75th percentiles , 39 and 59 beats/min ) . An abnormal heart rate recovery of 42 beats/min or less was seen in 1715 participants ( 33 % ) . Baseline and exercise characteristics of the study participants according to heart rate recovery are summarized in Table 1 . Table 1 . Baseline and Exercise Characteristics according to Heart Rate Recovery after Exercise Heart Rate Recovery and Mortality During 12 years of follow-up , 325 patients ( 6.2 % ) died . According to U.S. life tables , the actuarial predicted death rate was 7 % . Abnormal heart rate recovery was strongly predictive of death ( 10 % compared with 4 % among participants with normal heart rate recovery ; relative risk , 2.58 [ 95 % CI , 2.06 to 3.20 ] ) ( P<0.001 ) . The sensitivity , specificity , and positive and negative predictive values of an abnormal heart rate recovery for prediction of death over 12 years were 54 % , 69 % , 10 % , and 96 % , respectively . Of the participants who died , 116 ( 36 % ) were thought to have died of cardiovascular causes . An abnormal heart rate recovery was even more strongly predictive of cardiovascular death than of death in general ( 4 % compared with 1 % ; relative risk , 3.06 [ CI , 2.10 to 4.44 ] ) ( P<0.001 ) . Results of analyses stratified by age , sex , chronotropic response to exercise , regular exercise , smoking , resting hemodynamics , cholesterol level , and use of vasodilator medication are shown in Table 2 . Abnormal heart rate recovery was predictive of death in all subgroups except participants taking vasodilators . Table 2 . Association of Abnormal Heart Rate Recovery with Mortality according to Prespecified Subgroups Multivariable Cox Regression Analyses After adjustment for age , sex , body mass index , ethnicity , resting systolic blood pressure , use of vasodilators , exercise habits , physical fitness , smoking , diabetes , lipid profiles , ST-segment response , resting heart rate , chronotropic index , and educational and socioeconomic status and after consideration of interaction terms , a slower decrease in heart rate remained predictive of death ( adjusted relative risk , 1.55 [ CI , 1.22 to 1.98 ] ) ( P<0.001 by chi-square test ) . The adjusted attributable risk for death related to abnormal heart rate recovery was 15 % ( CI , 7 % to 24 % ) . Abnormal heart rate recovery was also predictive of cardiovascular death after adjustment for potential confounders and interactions ( adjusted relative risk , 1.95 [ CI , 1.11 to 3.42 ] ) ( P=0.02 ) . Discussion Heart rate recovery after submaximal exercise was a powerful predictor of mortality in a population -based cohort of adults without clinical ly evident cardiovascular disease , even after we adjusted for multiple , potentially confounding factors . These findings confirm the results of our previous study ( 1 ) and exp and them by demonstrating the prognostic importance of heart rate recovery in healthy persons undergoing submaximal , as opposed to symptom-limited , exercise testing . Heart rate recovery may therefore be a clinical ly relevant predictor of risk among patients undergoing screening exercise testing . Furthermore , because an abnormal heart rate recovery accounted for 15 % of deaths , this measure may be useful for insurance underwriting assessment s. It has been suggested that the link between heart rate recovery and mortality may be related to vagal tone and physical fitness ( 12 ) . We also noted an association between fitness levels and recovery heart rate ;  participants with abnormal heart rate recovery were less likely to exercise regularly and to participate in strenuous exercise ( Table 1 ) . It should be noted that heart rates Objective To study abnormalities in the resting ECG as independent predictors for all cause , cardiovascular disease ( CVD ) , and coronary heart disease ( CHD ) mortality in a population based r and om sample of men and women , and to explore whether their prognostic value is different between sexes . Design and subjects An age and sex stratified r and om sample was selected from the total Belgian population aged 25 to 74 years .  Baseline data were gathered and resting ECGs were classified according to Minnesota code criteria . The sample was then followed for at least 10 years with respect to cause specific death . Results are based on observations from 5208 men and 4746 women free from prevalent CHD at the start of the follow up period . Results Although the prevalence of major abnormalities in general was comparable between sexes , women had more ischaemic findings , ST segment changes , and abnormal T waves on their baseline ECG , while men showed more arrhythmias , bundle branch blocks , and left ventricular hypertrophy . Fitting the multiplicative effect on subsequent mortality between all ECG classifications under study and sex indicated that the prognostic value of ECG changes was equal in women and men . Independently of other risk factors and other major ECG changes , almost all ECG classifications were significantly related to all cause , CVD , and CHD mortality . The most predictive ECG findings for CVD death were ST segment depression ( risk ratio ( RR ) 4.71 ) , major ECG findings ( RR 3.26 ) , left ventricular hypertrophy ( RR 2.79 ) , bundle branch blocks ( RR 2.58 ) , T wave flattening ( RR 2.47 ) , ischaemic ECG findings ( RR 2.35 ) , and arrhythmias ( RR 2.15 ) . The prognostic value of major ECG findings for CVD and CHD death was more powerful than well established cardiovascular risk factors . Conclusions Abnormalities in the baseline ECG are strongly associated with subsequent all cause , CVD , and CHD mortality . Their predictive value was similar for men and women Aim of the study was to analyze the predictive power on short term mortality of electrocardiographic findings in asymptomatic subjects belonging to sample s of the general population . In the Italian RIFLE Pooling Project ( Risk Factors and Life Expectancy ) 12 180 men and 10 373 women aged 30 to 69 years had a resting electrocardiogram ( ECG ) recorded at baseline examination . All of them were free from clinical ly symptomatic heart disease and represented 23 cohorts spread all over Italy .  ECGs were read by the Minnesota Code using 5 large categories of abnormalities , i.e. Q-QS abnormalities , ST-T abnormalities , high R. waves , major arrhythmias , and blocks . Some clinical ly relevant ECG combination of abnormalities were also analyzed . Six-year mortality from coronary heart disease ( CHD ) , cardiovascular diseases ( CVD ) and all-cause mortality ( ALL ) were the end-point . Those ECG findings were relatively common and covered the majority ( 80 to 90 % ) of all abnormalities found in the general population before excluding subjects with symptomatic heart disease . Most ECG findings on most occasions were associated with an excess mortality from the three end-points in both men and women and among relatively young ( age 30 - 49 ) and mature ( age 50 - 69 ) adults . The strongest predictor of fatal events were Q-QS items and blocks . The most consistent predictors were ST-T findings , although this was true for men and not for women . Relative risk against the absence of abnormalities ( one by one and all together ) were adjusted by multivariate analysis feeding in the models some possible confounders , i.e. age , systolic blood pressure , serum cholesterol , cigarette consumption and body mass index . Relative risks in cells with more than 20 events ( cells being separately made by men , women , the 5 ECG findings categories and the 3 end-points ) were ranging 1.00 to 9.88 for Q-QS abnormalities , 1.03 to 3.76 for ST-T abnormalities , 1.28 to 5.14 for high R waves , 0.81 to 2.28 for arrhythmias and 0.79 to 3.59 for blocks . Most of these relative risks were statistically significant . Combinations of clinical ly relevant ECG findings in the same individual ( LVH , possible and definite myocardial infa rct ion ) were rare but carried a severe prognosis with high and statistically significant relative risks among men ( ranging between 3.19 and 7.24 ) while they could not be properly tested in most cells for women due to the small numbers involved . It is concluded that in the general population high rates of prevalent ignored ECG abnormalities in asymptomatic subjects are associated with significant excess mortality from CHD , CVD and all-cause mortality , suggesting a high prevalence of silent heart disease Exercise testing in asymptomatic persons has been criticized for failing to accurately predict those at risk for coronary heart disease ( CHD ) . Previous studies on asymptomatic subjects , however , may not have been large enough or long enough to provide reliable outcome measures . This study examines the ability of a maximal exercise test to predict death from CHD and death from any cause in a population of asymptomatic men . This is a prospect i ve longitudinal study performed between 1970 and 1989 , with an average follow-up of 8.4 years . The subjects are 25,927 healthy men , 20 to 82 years of age at baseline ( mean 42.9 years ) who were free of cardiovascular disease and who were evaluated in a preventive medicine clinic . The main outcome measures are CHD mortality and all-cause mortality . During follow-up there were 612 deaths from all causes and 158 deaths from CHD . The sensitivity of an abnormal exercise test to predict coronary death was 61 % . The age-adjusted relative risk of an abnormal exercise test for CHD death was 21 ( 6.9 to 63.3 ) in those with no risk factors , 27 ( 10.7 to 68.8 ) in those with 1 risk factor , 54 ( 21.5 to 133.7 ) in those with 2 risk factors , and 80 ( 30.0 to 212 . 5 ) in those with > /=3 factors . A maximal exercise test performed in asymptomatic men free of cardiovascular disease does appear to be a worthwhile tool in predicting future risk of CHD death . An abnormal exercise test is a more powerful predictor of risk in those with than without conventional risk factors CONTEXT The usefulness of exercise stress test results and global cardiovascular risk systems for predicting all-cause mortality in asymptomatic individuals seen in clinical setting s is unclear . OBJECTIVES To determine the validity for prediction of all-cause mortality of the Framingham Risk Score and of a recently described European global scoring system Systematic Coronary Risk Evaluation ( SCORE ) for cardiovascular mortality among asymptomatic individuals evaluated in a clinical setting and to determine the potential prognostic value of exercise stress testing once these baseline risks are known . DESIGN , SETTING , AND PARTICIPANTS Prospect i ve cohort study of 3554 asymptomatic adults between the ages of 50 and 75 years who underwent exercise stress testing as part of an executive health program between October 1990 and December 2002 ; participants were followed up for a mean of 8 years . MAIN OUTCOME MEASURES Global risk based on the Framingham Risk Score and the European SCORE . Prospect ively recorded exercise stress test result abnormalities included impaired physical fitness , abnormal heart rate recovery , ventricular ectopy , and ST-segment abnormalities . The primary end point was all-cause mortality . RESULTS There were 114 deaths . The c-index , which corresponds to receiver operating characteristic curve values , and the Akaike Information Criteria found that the European SCORE was superior to the Framingham Risk Score in estimating global mortality risk . In a multivariable model , independent predictors of death were a higher SCORE ( for 1 % predicted increase in absolute risk , relative risk [ RR ] , 1.07 ; 95 % confidence interval [ CI ] , 1.04 - 1.09 ; P<.001 ) , impaired functional capacity ( RR , 2.95 ; 95 % CI , 1.98 - 4.39 ; P<.001 ) , and an abnormal heart rate recovery ( RR , 1.59 ; 95 % , 1.04 - 2.41 ; P = .03 ) . ST-segment depression did not predict mortality . Among patients in the highest tertile from the SCORE , an abnormal exercise stress test result , defined as either impaired functional capacity or an abnormal heart rate recovery , identified a mortality risk of more than 1 % per year . CONCLUSION Exercise stress testing when combined with the European global risk SCORE may be useful for stratifying risk in asymptomatic individuals in a comprehensive executive health screening program Summary of the Recommendations The U.S. Preventive Services Task Force ( USPSTF ) concludes that the evidence is insufficient to recommend for or against routinely screening asymptomatic adults for type 2 diabetes , impaired glucose tolerance , or impaired fasting glucose . This is a grade I recommendation . ( See Appendix Table 1 for a description of the USPSTF classification of recommendations . ) The USPSTF found good evidence that available screening tests can accurately detect type 2 diabetes during an early , asymptomatic phase . ( See Appendix Table 2 for a description of the USPSTF classification of levels of evidence . ) The USPSTF also found good evidence that intensive glycemic control in patients with clinical ly detected ( not screening detected ) diabetes can reduce the progression of microvascular disease . However , the benefits of tight glycemic control on microvascular clinical outcomes take years to become apparent . It has not been demonstrated that beginning diabetes control early as a result of screening provides an incremental benefit compared with initiating treatment after clinical diagnosis . Existing studies have not shown that tight glycemic control significantly reduces macrovascular complications , including myocardial infa rct ion and stroke . The USPSTF found poor evidence to assess possible harms of screening . As a result , the USPSTF could not determine the balance of benefits and harms of routine screening for type 2 diabetes . The USPSTF recommends screening for type 2 diabetes in adults with hypertension or hyperlipidemia . This is a grade B recommendation . The USPSTF found good evidence that , in adults who have hypertension and clinical ly detected diabetes , lowering blood pressure below conventional target blood pressure values reduces the incidence of cardiovascular events and cardiovascular mortality ; this evidence is considered fair when extrapolated to cases of diabetes detected by screening . Among patients with hyperlipidemia , there is good evidence that detecting diabetes substantially improves estimates of individual risk for coronary heart disease , which is an integral part of decisions about lipid-lowering therapy . Clinical Considerations In the absence of evidence of direct benefits of routine screening for type 2 diabetes , the decision to screen individual patients is a matter of clinical judgment . Patients at increased risk for cardiovascular disease may benefit most from screening for type 2 diabetes , since management of cardiovascular risk factors leads to reductions in major cardiovascular events . Clinicians should assist patients in making that choice . In addition , clinicians should be alert to symptoms suggestive of diabetes ( for example , polydipsia and polyuria ) and test anyone with these symptoms . Screening for diabetes in patients with hypertension or hyperlipidemia should be part of an integrated approach to reduce cardiovascular risk . Lower targets for blood pressure ( that is , diastolic blood pressure 80 mm Hg ) are beneficial for patients with diabetes and high blood pressure . The third report of the Adult Treatment Panel III of the National Cholesterol Education Program recommends lower targets for low-density lipoprotein cholesterol for patients with diabetes . Attention to other risk factors , such as physical inactivity , diet , and overweight , is also important , both to decrease risk for heart disease and to improve glucose control . Three tests have been used to screen for diabetes : fasting plasma glucose ( FPG ) , 2-hour postload plasma glucose , and hemoglobin A1c .  The American Diabetes Association ( ADA ) has recommended the FPG test for screening ( values 6.99 mmol/L [ 126 mg/dL ] indicate diabetes ) because it is easier and faster to perform , more convenient and acceptable to patients , and less expensive than other screening tests . The FPG test is more reproducible than the 2-hour plasma glucose test , has less intraindividual variation , and has similar predictive value for development of microvascular complications of diabetes . Compared with the FPG test , the 2-hour plasma glucose test may lead to more individuals being diagnosed as diabetic . Hemoglobin A1c is more closely related to FPG than to 2-hour plasma glucose , but at the usual cut-points it is less sensitive in detecting lower levels of hyperglycemia . The r and om  capillary blood glucose test has been shown to have reasonable sensitivity ( 75 % at a cut-point of 6.66 mmol/L [ 120 mg/dL ] ) in detecting persons who have an FPG level greater than or equal to 6.99 mmol/L ( 126 mg/dL ) or a 2-hour plasma glucose level greater than or equal to 11.1 mmol/L ( 200 mg/dL ) , if results are interpreted according to age and time since last meal ; however , the r and om blood glucose test is less well st and ardized for screening for diabetes . The ADA recommends confirmation of a diagnosis of diabetes with a repeated FPG test on a separate day , especially for patients with borderline FPG results and patients with normal FPG levels for whom suspicion of diabetes is high . The optimal screening interval is not known . The ADA , on the basis of expert opinion , recommends an interval of every 3 years but shorter intervals in high-risk persons . Regardless of whether the clinician and patient decide to screen for diabetes , patients should be encouraged to exercise , eat a healthy diet , and maintain a healthy weight , choices that may prevent or forestall the development of type 2 diabetes . More aggressive interventions to establish and maintain these behaviors should be considered for patients at increased risk for diabetes , such as those who are overweight , have a family history of diabetes , or have a racial or ethnic background associated with an increased risk ( for example , Native American persons ) .  Intensive programs of lifestyle modification ( diet , exercise , and behavior ) should also be considered for patients who have impaired fasting glucose or impaired glucose tolerance , since several large trials have demonstrated that these programs can significantly reduce the incidence of diabetes in these patients . Evidence and recommendations regarding counseling about diet , physical activity , and obesity are provided in the USPSTF evidence summaries Counseling to Promote a Healthy Diet , Counseling to Promote Physical Activity , and Screening and Treatment for Obesity in Adults , available on the Agency for Healthcare Research and Quality Web site at www.preventiveservices.ahrq.gov . The brief review of the evidence that is normally included in USPSTF recommendation statements is available in the complete recommendation and rationale statement on the USPSTF Web site ( www.preventiveservices.ahrq.gov ) . Recommendations of Others The ADA acknowledged that data from prospect i ve studies were insufficient to determine the benefits of diabetes screening and thus concluded that the decision to test for diabetes should be based on clinical judgment and patient preference ( 1 ) . On the basis of expert consensus , the ADA recommends clinicians consider screening for diabetes with the FPG test beginning at age 45 years and at a younger age for individuals with such risk factors as family history , overweight , and hypertension , among others . The American College of Obstetricians and Gynecologists endorses the ADA recommendations ( 2 ) . The American Heart Association recommends measuring fasting blood glucose in persons 20 years of age and older according to risk for diabetes , as part of overall risk assessment for cardiovascular disease ( 3 ) . The Canadian Task Force on Preventive Health Care is currently updating its recommendations on diabetes screening BACKGROUND Before any new diagnostic test is accepted in clinical practice , such a test should be compared with established diagnostic tools in an appropriately large series of patients encompassing the complete spectrum of challenges to which the test is exposed . The aim of the present study was to assess the relative diagnostic and prognostic accuracies of high-dose dipyridamole echocardiography ( two-dimensional echocardiographic monitoring during dipyridamole infusion up to 0.84 mg/kg over 10 hours ) versus maximal symptom-limited bicycle exercise ECG test in patients with angina . METHODS AND RESULTS We studied 429 consecutive in-hospital patients who met the following inclusion criteria : history of chest pain , off antianginal therapy for at least 2 days ( 1 week for beta-blockers ) , no previous myocardial infa rct ion and /or obvious regional left ventricular dyssynergy of contraction ( akinesis or dyskinesis ) at baseline , and acceptable acoustic window under resting conditions . All patients underwent dipyridamole echocardiography and exercise ECG -- on different days and in r and om order -- within 1 week of coronary angiography ( which was performed independent of test results ) and were followed up for 37.8 + /- 14 months ( range , 1 to 73 months ) . Criteria of positivity were for dipyridamole echocardiography , a transient regional dyssynergy absent in the baseline examination ; for exercise ECG , an ST-segment shift of > or = 0.1 mV from baseline ; and for coronary angiography , a luminal reduction of > or = 75 % in at least one major coronary vessel ( 50 % for left main ) . There were 183 patients without and 246 with coronary artery disease ; 132 had one- , 70 had two- , and 44 had three- and /or left main vessel disease . The specificity was higher for dipyridamole echocardiography than for exercise ECG ( 90 % versus 51 % , P < .001 ) . The overall sensitivity of dipyridamole echocardiography  was similar to that of  exercise ECG  ( 75 % versus 74 % , P = NS ) , with no significant differences in the subset with one- ( 67 % versus 69 % , P = NS ) , two- ( 79 % versus 77 % , P = NS ) , or three- ( 93 % versus 86 % , P = NS ) vessel disease . During the follow-up , there were 20 deaths , 13 nonfatal myocardial infa rct ions , and 126 revascularization procedures . In the univariate analysis , dipyridamole result ed in higher chi 2 values than did exercise stress testing . A Cox forward stepwise survival analysis identified the  dipyridamole time as the most powerful prognostic predictor of death ( chi 2 = 19.4 , P < .0001 ) of all invasive and noninvasive parameters . The dipyridamole time also provided independent and additional prognostic information when it was adjusted for age , diabetes , resting ECG , and exercise stress test according to a modified , interactive stepwise procedure . This is true when death only , death and myocardial infa rct ion , and death , myocardial infa rct ion , and revascularization procedures were considered end points . CONCLUSIONS In patients with no previous myocardial infa rct ion and good resting left ventricular function , compared with exercise ECG , dipyridamole echocardiography has a similar sensitivity and a higher specificity for the noninvasive detection of angiographically assessed coronary artery disease . Dipyridamole echocardiography also provides information in addition to that provided by exercise ECG for predicting death , infa rct ion , and all events when the presence as well as the timing , severity , and extension of  dipyridamole-induced wall motion abnormalities are considered The associations of many electrocardiographic ( ECG ) abnormalities at rest with incident coronary heart disease ( CHD ) are not completely established , and whether individual ECG abnormalities convey similar risk across gender and race is uncertain . We studied the independent association of several ECG findings with incident CHD , testing for effect modification by gender and race , in a large , population -based , prospect i ve cohort study . Findings from the baseline 12-lead electrocardiograms in 1987 to 1989 were classified according to the Minnesota Code in 12,987 black and white men and women , aged 45 to 64 years , who were initially free of CHD and the use of specific cardiac medications . The incidence of CHD was ascertained through 2000 . After adjustment for multiple cardiovascular risk factors , the ECG findings that had the highest hazard rate ratios ( HRRs ) for incident CHD , when considered singly , were left ventricular hypertrophy with ST-T strain pattern in white men ( HRR 6.50 ) and in black women ( HRR 2.31 ) and , in the whole cohort , major ( HRR 2.27 ) and minor ( HRR 2.47 ) ST depression and major T-wave abnormalities ( HRR 2.12 ) . Statistically significant associations were also found in the whole cohort for minor Q waves and left ventricular hypertrophy by the Cornell definition , but not for a prolonged QTc interval , major ventricular conduction defects , or ST elevation . In conclusion , several 12-lead ECG findings were independently associated with incident CHD in middle-aged adults . With only a few exceptions , the associations were similar for blacks and whites OBJECTIVES This study was conducted to determine the incidence of physiologically significant coronary artery disease in a group of asymptomatic high risk men with essential hypertension and to assess the validity of noninvasive tests in a subset of these patients undergoing coronary arteriography . METHODS Two hundred twenty-six asymptomatic men ( mean age 61 + /- 8 years ) with essential hypertension and no clinical evidence of coronary artery disease but with at least one additional coronary risk factor were studied prospect ively . Fifty age- and risk factor-matched normotensive subjects were evaluated as a control group . After a minimum of 4 days without medication , subjects underwent stress thallium-201 scintigraphy , exercise and 48-h ambulatory electrocardiography , and echocardiography . Coronary angiography was performed in a subset of 34 ( 40 % ) of 84 patients with one or more positive test results . RESULTS A positive  thallium-201 scintigram  ( 18 % vs. 6 % ; odds ratio 3.4 , confidence interval 0.95 to 10.8 , p = 0.056 ) ,  exercise electrocardiograms ( ECGs ) ( 37 % vs. 13 % ; odds ratio 4.1 , confidence interval 1.5 to 11.2 , p < 0.003 ) and ambulatory ECG  ( 15 % vs. 0 % , p < 0.05 ) were more common in the hypertensive group than in the control group . In the cohort undergoing coronary angiography , thallium-201 scintigraphy was both sensitive and specific for epicardial atherosclerotic coronary disease ( 90 % and 79 % , respectively ) , but positive exercise and ambulatory ECGs occurred frequently in the absence of significant coronary stenoses . In the 39 % of hypertensive patients who had mild to moderate left ventricular hypertrophy , positive exercise and ambulatory ECGs occurred at a higher rate . CONCLUSIONS These findings suggest that physiologically significant coronary artery disease occurs more frequently in asymptomatic hypertensive men than in comparable normotensive control subjects . In the subgroup undergoing coronary arteriography , reversible scintigraphic defects were both sensitive and specific for diagnosing epicardial coronary artery disease , but exercise and ambulatory ECGs appeared to yield frequent false positive results , especially when left ventricular hypertrophy was present . These results indicate that patients with " silent " coronary artery disease can be identified among high risk hypertensive patients , but the appropriate application of such screening in clinical practice remains to be determined Importance Screening for asymptomatic bacteriuria can identify patients for whom treatment might be beneficial for preventing symptomatic infection and other health outcomes . Objective To systematic ally review benefits and harms of  asymptomatic bacteriuria screening and treatment in adults , including during pregnancy , to inform the US Preventive Services Task Force . Data Sources MEDLINE , PubMed ( publisher-supplied records ) , and Cochrane Collaboration Central Registry of Controlled Trials ; surveillance through May 24 , 2019 . Study Selection R and omized clinical trials ( RCTs ) and observational studies on benefits and harms of screening for asymptomatic bacteriuria ; RCTs on benefits and harms of asymptomatic bacteriuria treatment .  Eligible population s included unselected , asymptomatic individuals without known urinary tract conditions . Data Extraction and Synthesis Independent critical appraisal and data abstract ion by 2 review ers . R and om-effects meta- analysis was conducted to estimate benefits of the interventions . Main Outcomes and Measures Symptomatic infection ; function , morbidity , mortality ; pregnancy complications and birth outcomes . Results Nineteen studies ( N = 8443 ) meeting inclusion criteria were identified . Two cohort studies ( n = 5289 ) found fewer cases of pyelonephritis in the cohorts of screened pregnant women ( 0.5 % ) than within retrospective comparisons of unscreened cohorts ( 2.2 % and 1.8 % ) ; the larger study estimated a statistically significant relative risk of 0.30 ( 95 % CI , 0.15 - 0.60 ) . No studies examined screening in nonpregnant population s. Among 12 trials of asymptomatic bacteriuria screening and treatment during pregnancy ( n = 2377 ; 1 conducted within past 30 years ) , there were reduced rates of pyelonephritis ( range , 0%-16.5 % for the intervention group and 2.2%-36.4 % for the control group ; pooled risk ratio [ RR ] , 0.24 [ 95 % CI , 0.14 - 0.40 ] ; 12 trials ) and low birth weight ( range , 2.5%-14.8 % for the intervention group and 6.7%-21.4 % for the control group ; pooled RR , 0.64 [ 95 % CI , 0.46 - 0.90 ] ; 7 trials ) . There was no significant difference in infant mortality ( pooled RR , 0.98 [ 95 % CI , 0.29 - 3.26 ] ; 6 trials ) . Five RCTs of asymptomatic bacteriuria treatment in nonpregnant adults ( n = 777 ) did not report any significant differences in risk of infection , mobility , or mortality . Limited evidence on harms of screening or treatment was available , and no statistically significant differences were identified . Conclusions and Relevance Screening and treatment for asymptomatic bacteriuria during pregnancy was associated with reduced rates of pyelonephritis and low birth weights , but the available evidence was not current , with only 1 study conducted in the past 30 years . Benefits of asymptomatic bacteriuria treatment in nonpregnant adult population s were not found . Trial evidence on harms of asymptomatic bacteriuria antibiotic treatment was limited The Multiple Risk Factor Intervention Trial ( MRFIT ) was a r and omized primary prevention trial to test whether a special intervention ( SI ) program to reduce high blood pressure , elevated blood cholesterol , and /or cigarette smoking could lower  coronary heart disease ( CHD ) mortality in middle-aged men at above average risk . After an average follow-up period of 7 years , risk factor levels were reduced substantially more in SI than in usual-care ( UC ) men ; however , SI-UC differences in CHD mortality ( 7.1 % ) and total mortality ( -2.1 % ) were not statistically significant . Subgroup analysis showed 35 % fewer SI than UC CHD deaths ( P = 0.14 ) but no all-causes mortality difference in men comparable to the cohort having dietary and smoking intervention in Oslo ( the " Oslo-like " cohort ) . Among the subgroup hypertensive at entry , SI-UC differences in CHD and total mortality appeared to be heterogeneous : CHD mortality was 24 % lower in SI than UC men with a normal resting ECG at baseline , but 67 % higher if baseline ECG abnormalities were present ( nominal P = 0.02 , for difference in relative risk estimates ) . These findings were supported by within-group analyses and are generally consistent with results of other CHD/cardiovascular disease prevention trials . They pose a new hypothesis about possible adverse effects of diuretic therapy in a minority of the hypertensive population The objective of this report is the development of a population -specific prediction rule based on clinical and exercise test data that would estimate the risk of cardiovascular death in patients selected for cardiac catheterization . Prospect i ve data and follow-up information were obtained from patients who underwent cardiac catheterization soon after clinical assessment and exercise testing . Males ( n = 588 ) referred for evaluation of coronary heart disease from 1984 to 1990 were selected after exclusion of patients with significant valvular heart disease and patients with prior cardiac surgery . Half had a prior myocardial infa rct ion and half complained of typical angina pectoris . All patients performed a treadmill test and were selected for clinical reasons to undergo coronary angiography within 3 months . Over a mean follow-up period of 2.5 years ( + /- 1.4 years ) , there were 39 cardiovascular deaths and 45 nonfatal myocardial infa rct ions . The Cox proportional hazards model demonstrated the following characteristics to be statistically significant independent predictors of time until cardiovascular death : history of congestive heart failure ( hazards ratio of 4 ) , ST depression on the resting ECG ( hazards ratio of 3 ) , and a drop in systolic blood pressure below the resting value during exercise ( hazards ratio of 5 ) . Exercise-induced ST depression was not associated with either death or nonfatal myocardial infa rct ion . A simple score based on one item of clinical information ( history of congestive heart failure ) , a resting ECG finding ( ST depression ) , and an  exercise test response ( exertional hypotension ) stratified our patients for 4 years after testing from 75 % with a low risk ( annual cardiac mortality rate of 1 % ) , 17 % with a moderate risk ( annual mortality rate of 7 % ) , and 1 % with a high risk ( annual cardiac mortality rate of 12 % , with a hazards ratio of 20 and 95 % confidence interval from 6 to 70X ) . It was concluded that the variables available from the usual noninvasive workup of patients with known or suspected coronary artery disease enable prediction of risk of cardiovascular death . Three quarters of those usually undergoing cardiac catheterization can be identified by simple noninvasive variables as being at such low risk that invasive intervention is unlikely to improve prognosis Background — There is a paucity of r and omized trials regarding diagnostic testing in women with suspected coronary artery disease ( CAD ) . It remains unclear whether the addition of myocardial perfusion imaging ( MPI ) to the st and ard ECG exercise treadmill test ( ETT ) provides incremental information to improve clinical decision making in women with suspected CAD . Methods and Results — We r and omized symptomatic women with suspected CAD , an interpretable ECG , and ≥5 metabolic equivalents on the Duke Activity Status Index to 1 of 2 diagnostic strategies : ETT or exercise MPI . The primary end point was 2-year incidence of major adverse cardiac events , defined as CAD death or hospitalization for an acute coronary syndrome or heart failure . A total of 824 women were r and omized to ETT or exercise MPI . For women r and omized to ETT , ECG results were normal in 64 % , indeterminate in 16 % , and abnormal in 20 % . By comparison , the exercise MPI results were normal in 91 % , mildly abnormal in 3 % , and moderate to severely abnormal in 6 % . At 2 years , there was no difference in major adverse cardiac events ( 98.0 % for ETT and 97.7 % for MPI ; P=0.59 ) . Compared with ETT , index testing costs were higher for exercise MPI ( P<0.001 ) , whereas downstream procedural costs were slightly lower ( P=0.0008 ) . Overall , the cumulative diagnostic cost savings was 48 % for ETT compared with exercise MPI ( P<0.001 ) . Conclusions — In low-risk , exercising women , a diagnostic strategy that uses ETT versus exercise MPI yields similar 2-year posttest outcomes while providing significant diagnostic cost savings . The ETT with selective follow-up testing should be considered as the initial diagnostic strategy in symptomatic women with suspected CAD . Clinical Trial Registration — http://www . clinical trials.gov . Unique identifier : NCT00282711 Background : Asymptomatic ischaemic heart disease ( IHD ) in HIV-infected patients has not been studied . Methods : Resting , 12-lead electrocardiograms ( ECG ) were evaluated for asymptomatic IHD ( Q-wave and /or ST segment depression ) at baseline from HIV-infected participants with no known IHD enrolling in the SMART study . The ECG recordings were st and ardized and central ly analysed . Factors associated with asymptomatic IHD were identified by logistic regression , sequentially adjusted for demographics , clinical history , metabolic risk factors and type and duration of antiretroviral therapy ( ART ) . Results : Of 4831 participants with an evaluable , baseline ECG and no prior IHD , mean age was 44 years ( SD , 9.3 ) ; 28.4 % were female ; 6.6 % had diabetes ; 16.5 % were receiving antihypertensive therapy ; and 95.4 % were ART experienced .  ECG evidence of IHD was detected in 526 ( 10.9 % ) [ Q-wave in 283 ( 5.9 % ) , ST segment depression in 264 ( 5.5 % ) ] ; 16.7 % in those 60 years or older . Variables independently associated with these abnormalities were older age [ age ≥ 60 versus < 40 years : odds ratio ( OR ) , 2.2 ; 95 % confidence interval ( CI ) , 1.5–3.2 ; P < 0.001 ] , current antihypertensive therapy ( OR , 1.5 ; 95 % CI , 1.1–1.9 ; P = 0.003 ) and recruitment in Europe ( OR , 1.4 ; 95 % CI , 1.1–1.7 ; P = 0.004 ) or Asia ( OR , 1.6 ; 95 % CI , 1.0–2.6 ; P = 0.05 ) , both compared with North America . Diabetes was borderline significant ( OR , 1.4 ; 95 % CI , 1.0–2.0 ; P = 0.06 ) . Conclusions : ECG evidence of asymptomatic IHD was common in this large cohort of HIV-infected adults and more common than a history of symptomatic IHD . Traditional factors were the predominant determinants of risk . No clear association between ART type or duration and asymptomatic IHD was noted CONTEXT Data are sparse regarding the prevalence , incidence , and independent prognostic value of minor and /or major electrocardiographic ( ECG ) abnormalities in asymptomatic postmenopausal women . There is no information on the effect , if any , of hormonal treatment on the prognostic value of the ECG . OBJECTIVE To examine association of minor and major baseline and incident ECG abnormalities with long-term cardiovascular morbidity and mortality . DESIGN , SETTING , AND PARTICIPANTS Post-hoc analysis of the estrogen plus progestin component of the Women 's Health Initiative study , a r and omized controlled primary prevention trial of 14 749 postmenopausal asymptomatic women with intact uterus who received 1 daily tablet containing 0.625 mg of oral conjugated equine estrogen and 2.5 mg of medroxyprogesterone acetate or a matching placebo . Participants were enrolled from 1993 to 1998 , and the estrogen plus progestin trial was stopped on July 7 , 2002 . MAIN OUTCOME MEASURES The Novacode criteria were used to define minor , major , and incident ECG abnormalities . Cardiovascular end points included incident coronary heart disease ( CHD ) and cardiovascular disease ( CVD ) events . RESULTS Among women with absent ( n = 9744 ) , minor ( n = 4095 ) , and major ( n = 910 )  ECG abnormalities  , there were 118 , 91 , and 37 incident CHD events , respectively . The incident annual CHD event rates per 10 000 women with absent , minor , or major ECG abnormalities were 21 ( 95 % confidence interval [ CI ] , 18 - 26 ) , 40 ( 95 % CI , 32 - 49 ) , and 75 ( 95 % CI , 54 - 104 ) , respectively . After 3 years of follow-up , 5 % of women who had normal ECG at baseline developed new ECG abnormalities with an annual CHD event rate of 85 ( 95 % CI , 44 - 164 ) per 10 000 women . The adjusted hazard ratios for CHD events were 1.55 ( 95 % CI , 1.14 - 2.11 ) for minor baseline , 3.01 ( 95 % CI , 2.03 - 4.46 ) for major baseline , and 2.60 ( 95 % CI , 1.08 - 6.27 ) for incident ECG abnormalities . There were no significant interactions between hormone treatment assignment and ECG abnormalities for risk prediction of cardiovascular end points . For prediction of CHD events , the addition of ECG findings to the Framingham risk score increased from 0.69 to 0.74 the area under the receiver operating characteristic curve . Similar findings were found for incident CVD events . CONCLUSIONS Among asymptomatic postmenopausal women , clinical ly relevant baseline and incident ECG abnormalities are independently associated with increased risk of cardiovascular events and mortality , and the information is incremental to the established method of risk stratification . TRIAL REGISTRATION clinical trials.gov Identifier : NCT00000611 This issue of JAMA contains the latest US Preventive Services Task Force ( USPSTF ) recommendation statement on statins for prevention of cardiovascular disease in adults,1 along with the accompanying evidence report and systematic review 2 on which the recommendations are based . The evidence report summarized data from 19 trials including a total of 71 344 patients and concluded that statin therapy was associated with reduced risk of all-cause and cardiovascular mortality and cardiovascular disease ( CVD ) events . Thus , the task force recommended “ initiating use of lowto moderate-dose statins in adults aged 40 to 75 years without a history of CVD who have 1 or more CVD risk factors and a calculated 10-year CVD event risk of 10 % or greater ( B recommendation ) ” or “ 7.5 % to 10 % ( C recommendation ) .”1 Although the task force did their usual careful job of review ing the evidence , the evidence for treating asymptomatic persons with statins does not appear to merit a grade B or even a grade C recommendation . The task force evidence report estimated an absolute benefit for use of statins of 0.40 % for all-cause mortality and 0.43 % for cardiovascular mortality and indicated that the absolute benefit was greater for patients at greater baseline risk.2 Notably , the evidence report did not exclude studies that included patients taking statins for secondary prevention , who have a higher baseline risk of cardiac events and death and thus are more likely to benefit from therapy that inflates the benefit attributed to a primary prevention population . The task force did perform a sensitivity analysis that excluded 3 trials with persons for whom there were prior “ hard ” cardiovascular events and obtained similar results of benefits ( eTable 5 in the article by Chou et al2 ) . This sensitivity analysis did not exclude WOSCOPS , which included patients receiving statins for secondary prevention—5 % had angina and 3 % had intermittent claudication,3 accounting for 15 % of the total weight in the meta- analysis . In contrast , a meta- analysis of 11 studies and 65 229 patients receiving statins for primary prevention , in which patients receiving statins for secondary prevention were excluded , found no benefit of statins for reducing all-cause mortality.4 The confidence intervals of these 2 analyses overlap , and the difference between these findings likely reflects differences in studies included . The USPSTF and authors of the evidence report did not have access to the primary data ( clinical study reports and anonymized patient-level data ) from the statin clinical trials . Rather , they had to rely on peer- review ed published reports as the basis for these recommendations . Exacerbating the potential bias , all of the trials included in the task force evidence report2 were industry-sponsored except 1 trial,5 and that trial contributed 0.2 % of the weight to the mortality calculation . Industry-sponsored studies have been shown to report greater benefit and lesser adverse effects than noncommercially sponsored trials of the same drugs.6 Whether this is true for statins and primary prevention of CVD is unknown . Among the 19 r and omized clinical trials of statins vs placebo or no statin included in the evidence report for the task force recommendations , only 15 reported all-cause mortality , 10 reported cardiovascular mortality , 12 reported fatal and nonfatal myocardial infa rct ion  , and 13 reported fatal and nonfatal stroke.2,7  Reliance on selective reporting of the most important outcomes , which are likely included in the clinical trial data , makes reporting bias possible . Furthermore , after allcause mortality , the comparative incidence of serious adverse events between treatment and control groups is arguably the second most important measure of the effect of active therapy in r and omized clinical trials . Underst and ing the evidence base in evaluating harms of statin therapy is also critically important . Although the benefits of any preventive therapy accrue according to risk of disease ( greater benefit in higher-risk patients ) , the harms of therapy usually distribute equally over all risk levels . Thus , persons at low risk have little chance of benefit but equal chance of harms and thus are more likely to have a net harm . The evidence base for harms of statins , despite the introduction of these drugs more than 20 years ago , is incomplete . Many of the trials did not ask about commonly reported statin effects , such as muscle pains and weakness , and only recorded myopathy , for which an increase in creatine kinase levels was required . Because most muscle problems do not involve an increase in creatine kinase levels , this leads to a significant underestimate of muscle problems . Other studies have estimated that closer to 20 % of statin users have muscle problems.8 Additionally , the actual trial data are largely held by the Cholesterol Treatment Trialists ’ Collaboration on behalf of the industry sponsor and have not been made available to other research ers , despite multiple requests over many years.9 Although reported rates of adverse events in clinical trials are low , this does not reflect the experience of clinicians who see patients who are taking statins . For instance , the experience of an NPR reporter with a calculated 2.9 % risk of heart disease over 10 years using the recommended American College of Cardiology/American Heart Association ( ACC/AHA ) risk calculator,10 but still prescribed a statin , and experiencing adverse effects from the medication , is typical of what many Related articles at jama.com The U.S. Preventive Services Task Force ( USPSTF ) makes recommendations about the effectiveness of specific preventive care services for patients without related signs or symptoms . It bases its recommendations on the evidence of both the benefits and harms of the service and an assessment of the balance . The USPSTF does not consider the costs of providing a service in this assessment . The USPSTF recognizes that clinical decisions involve more considerations than evidence alone . Clinicians should underst and the evidence but individualize decision making to the specific patient or situation . Similarly , the USPSTF notes that policy and coverage decisions involve considerations in addition to the evidence of clinical benefits and harms . Summary of Recommendation and Evidence The USPSTF recommends annual screening for lung cancer with low-dose computed tomography ( LDCT ) in adults aged 55 to 80 years who have a 30 pack-year smoking history and currently smoke or have quit within the past 15 years . Screening should be discontinued once a person has not smoked for 15 years or develops a health problem that substantially limits life expectancy or the ability or willingness to have curative lung surgery . ( B recommendation ) See the Clinical Considerations section for suggestions for implementation in practice . See the Figure for a summary of the recommendation and suggestions for clinical practice . Figure . Screening for lung cancer : clinical summary of U.S. Preventive Services Task Force recommendation . Appendix Table 1 describes the USPSTF grade s , and Appendix Table 2 describes the USPSTF classification of levels of certainty about net benefit . Appendix Table 1 . What the USPSTF Grade s Mean and Suggestions for Practice Appendix Table 2 . USPSTF Levels of Certainty Regarding Net Benefit Supplement . Consumer Fact Sheet . Rationale Importance Lung cancer is the third most common cancer and the leading cause of cancer-related death in the United States ( 1 ) . The most important risk factor for lung cancer is smoking , which results in approximately 85 % of all U.S. lung cancer cases ( 2 ) . Although the prevalence of smoking has decreased , approximately 37 % of U.S. adults are current or former smokers ( 2 ) . The incidence of lung cancer increases with age and occurs most commonly in persons aged 55 years or older . Increasing age and cumulative exposure to tobacco smoke are the 2 most common risk factors for lung cancer . Lung cancer has a poor prognosis , and nearly 90 % of persons with lung cancer die of the disease . However , early-stage nonsmall cell lung cancer ( NSCLC ) has a better prognosis and can be treated with surgical resection . Detection Most lung cancer cases are NSCLC , and most screening programs focus on the detection and treatment of early-stage NSCLC . Although chest radiography and sputum cytologic evaluation have been used to screen for lung cancer , LDCT has greater sensitivity for detecting early-stage cancer ( 3 ) . Benefits of Detection and Early Treatment Although lung cancer screening is not an alternative to smoking cessation , the USPSTF found adequate evidence that annual screening for lung cancer with LDCT  in a defined population of high-risk persons can prevent a substantial number of lung cancerrelated deaths . Direct evidence from a large , well-conducted , r and omized , controlled trial ( RCT ) provides moderate certainty of the benefit of lung cancer screening with LDCT in this population ( 4 ) . The magnitude of benefit to the person depends on that person 's risk for lung cancer because those who are at highest risk are most likely to benefit . Screening can not prevent most lung cancerrelated deaths , and smoking cessation remains essential . Harms of Detection and Early Intervention and Treatment The harms associated with LDCT screening include false-negative and false-positive results , incidental findings , overdiagnosis , and radiation exposure . False-positive LDCT results occur in a substantial proportion of screened persons ; 95 % of all positive results do not lead to a diagnosis of cancer . In a high- quality screening program , further imaging can resolve most false-positive results ; however , some patients may require invasive procedures . The USPSTF found insufficient evidence on the harms associated with incidental findings . Overdiagnosis of lung cancer occurs , but its precise magnitude is uncertain . A modeling study performed for the USPSTF estimated that 10 % to 12 % of screen-detected cancer cases are overdiagnosedthat is , they would not have been detected in the patient 's lifetime without screening . Radiation harms , including cancer result ing from cumulative exposure to radiation , vary depending on the age at the start of screening ; the number of scans received ; and the person 's exposure to other sources of radiation , particularly other medical imaging . USPSTF Assessment The USPSTF concludes with moderate certainty that annual screening for lung cancer with LDCT is of moderate net benefit in asymptomatic persons who are at high risk for lung cancer based on age , total cumulative exposure to tobacco smoke , and years since quitting smoking . The moderate net benefit of screening depends on limiting screening to persons who are at high risk , the accuracy of image interpretation being similar to that found in the NLST ( National Lung Screening Trial ) , and the resolution of most false-positive results without invasive procedures ( 4 ) . Clinical Considerations Patient Population Under Consideration The risk for lung cancer increases with age and cumulative exposure to tobacco smoke and decreases with time since quitting smoking . The best evidence for the benefit of screening comes from the NLST , which enrolled adults aged 55 to 74 years who had at least a 30 pack-year smoking history and were current smokers or had quit within the past 15 years . As with all screening trials , the NLST tested a specific intervention over a finite period . Because initial eligibility extended through age 74 years and participants received 3 annual screening computed tomographic scans  , the oldest participants in the trial were aged 77 years . The USPSTF used modeling studies to predict the benefits and harms of screening programs that use different screening intervals , age ranges , smoking histories , and times since quitting . A program that annually screens adults aged 55 to 80 years who have a 30 pack-year smoking history and currently smoke or have quit within the past 15 years is projected to have a reasonable balance of benefits and harms . The model assumes that persons who achieve 15 years of smoking cessation during the screening program discontinue screening . This model predicts the outcomes of continuing the screening program used in the NLST through age 80 years . Screening may not be appropriate for patients with substantial comorbid conditions , particularly those at the upper end of the screening age range . The NLST excluded persons who were unlikely to complete curative lung cancer surgery and those with medical conditions that posed a substantial risk for death during the 8-year trial . The baseline characteristics of the NLST showed a relatively healthy sample , and fewer than 10 % of enrolled participants were older than 70 years ( 5 ) . Persons with serious comorbid conditions may experience net harm , no net benefit , or at least substantially less net benefit . Similarly , persons who are unwilling to have curative lung surgery are unlikely to benefit from a screening program . Assessment of Risk Age , total exposure to tobacco smoke , and years since quitting smoking are important risk factors for lung cancer and were used to determine eligibility in the NLST . Other risk factors include specific occupational exposures , radon exposure , family history , and history of pulmonary fibrosis or chronic obstructive lung disease . The incidence of lung cancer is relatively low in persons younger than 50 years but increases with age , especially after age 60 years . In current and former smokers , age-specific incidence rates increase with age and cumulative exposure to tobacco smoke . Smoking cessation substantially reduces a person 's risk for developing and dying of lung cancer . Among persons enrolled in the NLST , those who were at highest risk because of additional risk factors or a greater cumulative exposure to tobacco smoke experienced most of the benefit ( 6 ) . A vali date d multivariate model showed that persons in the highest 60 % of risk accounted for 88 % of all deaths preventable by screening . Screening Tests Low-dose computed tomography has shown high sensitivity and acceptable specificity for the detection of lung cancer in high-risk persons .  Chest radiography and sputum cytologic evaluation  have not shown adequate sensitivity or specificity as screening tests . Therefore , LDCT is currently the only recommended screening test for lung cancer . Treatment Surgical resection is the current st and ard of care for localized NSCLC . This type of cancer is treated with surgical resection when possible and also with radiation and chemotherapy . Annual LDCT screening may not be useful for patients with life-limiting comorbid conditions or poor functional status who may not be c and i date s for surgery . Other Approaches to Prevention Smoking cessation is the most important intervention to prevent NSCLC . Advising smokers to stop smoking and preventing nonsmokers from being exposed to tobacco smoke are the most effective ways to decrease the morbidity and mortality associated with lung cancer . Current smokers should be informed of their continuing risk for lung cancer and offered cessation treatments . Screening with LDCT should be viewed as an adjunct to tobacco cessation interventions . Useful Re sources Clinicians have many re sources to help patients stop smoking . The Centers for Disease Control and Prevention has developed a Web site with many such re sources , including information on tobacco quit lines , available in several language s ( www.cdc.gov/tobacco/campaign/tips ) . Quit Background —Exercise stress testing alone or with perfusion imaging is the st and ard screening method to determine the presence of obstructive coronary artery disease ( CAD ) in people with chest pain . In asymptomatic individuals with a family history of premature CAD , it is unclear whether abnormalities on these functional exercise tests represent significant coronary disease . Methods and Results —An abnormal exercise test , thallium scan , or both occurred in 153 ( 21 % ) of 734 asymptomatic siblings of persons with documented CAD , of whom 105 underwent coronary angiography with quantitative analysis of stenosis severity . Overall , 95 % had coronary atherosclerosis , but only 39 % had 1 or more stenoses with ≥50 % narrowing . Of 30 siblings in whom the exercise test and perfusion scan were both abnormal , 70 % had ≥50 % stenoses . The mean stenosis in arteries that fed perfusion defects was only 43±31 % , and 68 % of such stenoses were < 50 % . However , in 71 % of all defects , the location matched arteries with the most severe stenoses . Conclusions —In asymptomatic persons with a family history of CAD , abnormal exercise scintigraphy identifies predominantly mild coronary atherosclerosis . Perfusion defects may be caused by coronary vasomotor dysfunction in addition to atherosclerotic plaque BACKGROUND Approximately 3,000 new cases of oral cancer are diagnosed each year in Canada . Most of these cases occur among older adults with a history of tobacco use or excessive alcohol consumption . Preventive interventions for oral cancer include counselling of patients to modify risk factors and screening to identify precancerous and early-stage lesions . This report presents evidence -based guidelines on the prevention of oral cancer and precancer among asymptomatic patients . METHODS Literature search es of the 1966 - 1999 MEDLINE and CANCERLIT data bases were completed using the major MeSH heading mouth neoplasms . References from articles and recommendations of organizations were also review ed . The evidence -based methods of the Canadian Task Force on Preventive Health Care were used to assess evidence and to develop guidelines . Advice from experts and other recommendations were taken into consideration . RESULTS In cohort and case-control studies , smoking cessation decreased the risk of oral cancer and precancer . R and omized controlled trials ( RCTs ) indicate counselling by trained health care professionals is effective in promoting smoking cessation . Although counselling has been effective for the reduction of excessive alcohol consumption in RCTs , no studies have examined whether alcohol reduction reduces the risk of oral cancer or precancer . The usefulness of general population screening is limited by the low prevalence and incidence of the disease , the potential for false-positive diagnoses and the poor compliance with screening and referral . There is no evidence that screening of the general population or high-risk groups leads to a reduction in mortality or morbidity from oral cancer . INTERPRETATION There is good evidence to specifically consider smoking cessation counselling in a periodic health examination ( grade A recommendation ) . For population screening , there is fair evidence to specifically exclude screening for oral cancer ( grade D recommendation ) . For opportunistic screening during periodic examinations , there is insufficient evidence to recommend inclusion or exclusion of screening for oral cancer ( grade C recommendation ) . For patients at high risk , annual examination by physician or dentist should be considered . Risk factors include tobacco use and excessive consumption of alcohol . These recommendations are similar to those made by the Canadian Task Force on the Periodic Health Examination in 1994 and by the U.S. Preventive Services Task Force in 1996 CONTEXT Both attenuated heart rate recovery following exercise and the Duke treadmill exercise score have been demonstrated to be independent predictors of mortality , but their prognostic value relative to each other has not been studied . OBJECTIVE To assess the associations among abnormal heart rate recovery , treadmill exercise score , and death in patients referred specifically for exercise electrocardiography .  DESIGN AND SETTING Prospect i ve cohort study conducted in an academic medical center between September 1990 and December 1997 , with a median follow-up of 5.2 years . PATIENTS A total of 9454 consecutive patients ( mean [ SD ] age , 53 [ 11 ] years ; 78 % male ) who underwent symptom-limited exercise electrocardiographic testing . Exclusion criteria included age younger than 30 years , history of heart failure or valvular disease , pacemaker implantation , and uninterpretable electrocardiograms . MAIN OUTCOME MEASURES All-cause mortality , as predicted by abnormal heart rate recovery , defined as failure of heart rate to decrease by more than 12/min during the first minute after peak exercise , and by treadmill exercise score , defined as ( exercise time ) - ( 5 x maximum ST-segment deviation ) - ( 4 x treadmill angina index ) . RESULTS Three hundred twelve deaths  occurred in the cohort . Abnormal heart rate recovery and intermediate- or high-risk treadmill exercise score were present in 20 % ( n = 1852 ) and 21 % ( n = 1996 ) of patients , respectively . In univariate analyses , death was predicted by both abnormal heart rate recovery ( 8 % vs 2 % in patients with normal heart rate recovery ; hazard ratio [ HR ] , 4.16 ; 95 % confidence interval [ CI ] , 3.33 - 5.19 ; chi(2 ) = 158 ; P<.001 ) and intermediate- or high-risk treadmill exercise score ( 8 % vs 2 % in patients with low-risk scores ; HR , 4.28 ; 95 % CI , 3.43 - 5.35 ; chi(2 ) = 164 ; P<.001 ) . After adjusting for age , sex , st and ard cardiovascular risk factors , medication use , and other potential confounders , abnormal heart rate recovery remained predictive of death ( among the 8549 patients not taking beta-blockers , adjusted HR , 2.13 ; 95 % CI , 1.63 - 2.78 ; P<.001 ) , as did intermediate- or high-risk treadmill exercise score ( adjusted HR , 1 . 49 ; 95 % CI , 1.15 - 1.92 ; P = .002 ) . There was no interaction between these 2 predictors . CONCLUSIONS In this cohort of patients referred specifically for exercise electrocardiography  , both abnormal heart rate recovery and treadmill exercise score were independent predictors of mortality . Heart rate recovery appears to provide additional prognostic information to the established treadmill exercise score and should be considered for routine incorporation into exercise test interpretation . JAMA . 2000;284:1392 - 1398 Aim : This prospect i ve follow‐up study investigated long‐term exercise capacity at a mean age of 10 y after neonatal arterial switch operation for transposition of the great arteries in a large group of homogeneous unselected children . Methods : 56 asymptomatic children , aged 7.9–14.3 y ( 10.5 ± 1.6 , mean ± SD ) , were examined with respect to exercise tolerance , electrocardiographic ( ECG ) response and activity of biochemical markers for myocardial injury . The protocol included st and ard electrocardiography , M‐mode and two‐dimensional echocardiography at rest , a Bruce walking treadmill test to voluntary exhaustion , and determination of cardiac troponin I and T , creatine kinase and myoglobin from venous blood sample s at rest and 4 h after exercise . Heart rate , blood‐pressure response to exercise stress and endurance time were compared with published results of age‐matched normal children . Results : 54 patients ( 96.4 % ) had normal exercise capacity ; a reduction in 2 patients was not due to cardiac disease . Heart rate and systolic blood pressure rose significantly between rest and peak exercise and did not differ from normal controls , whereas diastolic blood pressure was lower . ECG remained normal at rest and on exercise in 54 children ( 96.4 % ) . Serum values of cardiac troponin I and T , creatine kinase and myoglobin were normal at rest and after exercise in all patients BACKGROUND Cancer screening is one approach to reducing cancer-related morbidity and mortality rates .  Screening strategies vary in intensity . Higher-intensity strategies are not necessarily higher value . High-value strategies provide a degree of benefits that clearly justifies the harms and costs incurred ; low-value screening provides limited or no benefits to justify the harms and costs . When cancer screening leads to benefits , an optimal intensity of screening maximizes value . Some aspects of screening practice s , especially overuse and underuse , are low value . METHODS Screening strategies for asymptomatic , average-risk adults for 5 common types of cancer were evaluated by review ing clinical guidelines and evidence syntheses from the American College of Physicians ( ACP ) , U.S. Preventive Services Task Force , American Academy of Family Physicians , American Cancer Society , American Congress of Obstetricians and Gynecologists , American Gastroenterological Association , and American Urological Association . " High value " was defined as the lowest screening intensity threshold at which organizations agree about screening recommendations for each type of cancer and " low value " as agreement about not recommending overly intensive screening strategies . This information is supplemented with additional findings from r and omized , controlled trials ; modeling studies ; and studies of costs or re source use , including information found in the National Cancer Institute 's Physician Data Query and UpTo Date . The ACP provides high-value care screening advice for 5 common types of cancer ; the specifics are outlined in this article . The ACP strongly encourages clinicians to adopt a cancer screening strategy that focuses on reaching all eligible persons with these high-value screening options while reducing overly intensive , low-value screening The major goal of the U.S. Preventive Services Task Force ( USPSTF ) is to provide clinicians and policymakers with a reliable and accurate source of evidence -based recommendations on a wide range of preventive services . To accomplish this goal , the USPSTF systematic ally review s the evidence concerning both the benefits and harms of widespread implementation of a preventive service . It then assesses the certainty of the evidence and the magnitude of the benefits and harms . On the basis of this assessment , the USPSTF assigns a letter grade to each preventive service signifying its recommendation about provision of the service ( Table 1 ) . Table 1 . U.S. Preventive Services Task Force Recommendation Grid * An important , but often challenging , step is determining the balance between benefits and harms to estimate net benefit ( that is , benefits minus harms ) . In this issue , the Task Force reports an up date to its recommendation for carotid artery stenosis screening ( 1 , 2 ) . Because carotid artery stenosis screening has both known benefits and harms , estimating net benefit was critical in the final USPSTF recommendation that clinicians not provide carotid artery stenosis screening in asymptomatic people ( recommendation letter grade D ) . Release of this recommendation provides an opportunity for the Task Force to up date and explain to a clinical audience the process by which it evaluates evidence , determines the certainty and magnitude of net benefit , and gives a letter grade to the recommendation . We will do this by considering 3 questions : 1 ) What evidence does the Task Force consider to estimate net benefit ? 2 ) How does the Task Force estimate the certainty of net benefit ? and 3 ) How does the Task Force estimate the magnitude of net benefit ? What Evidence Does the Task Force Consider to Estimate Net Benefit ? The overarching question that the Task Force seeks to answer for every preventive service is whether evidence suggests that provision of the service would improve health outcomes if implemented in a general primary care population . For screening topics , this st and ard could be met by a large r and omized , controlled trial ( RCT ) in a representative asymptomatic population with follow-up of all members of both the group invited for screening and the group not invited for screening . For example , the Multicentre Aneurysm Screening Study ( 3 ) was a population -based RCT of screening for abdominal aortic aneurysm in which 67800 asymptomatic men age 65 to 74 years in the United Kingdom were r and omly assigned to be invited or not to be invited for screening . Both groups were followed for a mean of 4.1 years , and abdominal aortic aneurysmrelated mortality and all-cause mortality were compared . No RCTs of carotid artery stenosis screening have been published ; however , RCTs comparing carotid endarterectomy to medical management of asymptomatic carotid artery stenosis are available . The distinction between RCTs that r and omly assign people to undergo screening  versus RCTs that r and omly assign people known to have a condition to an intervention is important . In contrast to the latter , RCTs of screening take into account the false-positive and false-negative rates of the screening test , the possibility of adverse events from the test , the accuracy and potential for adverse events of any subsequent confirmatory diagnostic tests , and the inevitable failure to follow through on the test or any subsequent steps needed before the therapeutic intervention is delivered . In addition , conditions detected by screening may have different biological characteristics than those detected in other ways . The benefits of treating screened individuals , therefore , can not be assumed to be the same as those of treating symptomatic individuals . Screening trials directly answer a simple question important to the primary care setting : Does screening for a certain condition improve health outcomes ? Direct RCT evidence about screening is often unavailable , so the Task Force considers indirect evidence . To guide its selection of indirect evidence , the Task Force constructs a chain of evidence within an analytic framework . Figure 1 of the evidence up date ( 2 ) in this issue ( page 861 ) shows the analytic framework for the Task Force assessment of carotid artery stenosis screening . Each arrow in the framework defines a key question , and each key question represents a link in the chain of evidence . Rectangles in the framework represent the intermediate outcomes ( rounded corners ) or the health outcomes ( square corners ) ; ovals represent harms . To form an unbroken chain , evidence must support each link in the chain , thereby connecting the target population ( far left side of the framework ) to the improved health outcome ( far right side of the framework ) . For each key question , the body of pertinent literature is critically appraised , focusing on 6 questions ( Table 2 ) . The USPSTF will now describe its judgment about the evidence for each key question as convincing , adequate , or inadequate . Evidence may be considered convincing when derived from several high- quality studies with consistent , logical results that are generalizable to the U.S. primary care population and setting . Evidence may be deemed adequate when , on the basis of judgment , most but not all of these 6 questions are answered favorably . When evidence is conflicting or the studies are of poor quality individually or in aggregate , the evidence for a key question is considered inadequate . Inadequate evidence may create a critical gap in the evidence chain . Table 2 . Questions Considered by the U.S. Preventive Services Task Force for Evaluating Evidence Related Both to Key Questions and to the Overall Certainty of the Evidence of Net Benefit for the Preventive Service How Does the Task Force Estimate the Certainty of Net Benefit ? The next step in the Task Force process is to use the evidence from the key questions to assess whether there would be net benefit if the service were implemented . In 2001 , the USPSTF published an article that documented its systematic processes of evidence evaluation and recommendation development ( 4 ) . At that time , the Task Force 's overall assessment of evidence was described as good , fair , or poor . The Task Force realized that this rating seemed to apply only to how well studies were conducted and did not fully capture all of the issues that go into an overall assessment of the evidence about net benefit . To avoid confusion , the USPSTF has changed its terminology . Whereas individual study quality will continue to be characterized as good , fair , or poor , the term certainty will now be used to describe the Task Force 's assessment of the overall body of evidence about net benefit of a preventive service and the likelihood that the assessment is correct . Certainty will be determined by considering all 6 questions in Table 2 ; the judgment about certainty will be described as high , moderate , or low . In making its assessment of certainty about net benefit , the evaluation of the evidence from each key question plays a primary role . It is important to note that the Task Force makes recommendations for real-world medical practice in the United States and must determine to what extent the evidence for each key question even evidence from screening RCTs or treatment RCTs can be applied to the general primary care population . Frequently , studies are conducted in highly selected population s under special conditions . The Task Force must consider differences between the general primary care population and the population s studied in RCTs and make judgments about the likelihood of observing the same effect in actual practice . For carotid artery stenosis screening , the Task Force search ed for evidence about the true prevalence of high- grade carotid artery stenosis in the general population , the generalizability of treatment effectiveness estimates based on RCTs conducted in selected population s , and the complication rate from carotid endarterectomy in asymptomatic individuals if performed in nontrial setting s ( for example , community hospitals ) . It is also important to note that 1 of the key questions in the analytic framework refers to the potential harms of the preventive service . The Task Force considers the evidence about the benefits and harms of preventive services separately and equally . Data about harms are often obtained from observational studies because harms observed in RCTs may not be representative of those found in usual practice and because some harms are not completely measured and reported in RCTs . For example , the surgeons who enrolled patients in RCTs of carotid artery stenosis were selected on the basis of their low postoperative stroke and mortality rates . Widespread screening for carotid artery stenosis would invariably lead to surgical treatment provided in hospitals ( or by surgeons ) with higher rates of complications . The harms of screening for carotid artery stenosis , including the harms from carotid angiography to confirm the diagnosis of carotid artery stenosis in patients screening positive by carotid ultrasonography  , were not captured in some treatment RCTs . Putting the body of evidence for all key questions together as a chain , the Task Force assesses the certainty of net benefit of a preventive service by asking the 6 major questions in Table 2 . The Task Force would rate a body of convincing evidence about the benefits of a service that , for example , derives from several RCTs of screening in which the estimate of benefits can be generalized to the general primary care population as high certainty ( Table 3 ) . The Task Force would rate a body of evidence that was not clearly applicable to general practice or has other defects in quality , research design , or consistency of studies as moderate certainty . Certainty is low when , for example , there are gaps in the evidence linking parts of the analytic framework , when evidence to determine the harms of treatment is unavailable , or CONTEXT Three major coronary risk factors-serum cholesterol level , blood pressure , and smoking-increase incidence of coronary heart disease ( CHD ) and related end points . In previous investigations , risks for low-risk reference groups were estimated statistically because sample s contained too few such people to measure risk . OBJECTIVE To measure long-term mortality rates for individuals with favorable levels for all 3 major risk factors , compared with others . DESIGN Two prospect i ve studies , involving 5 cohorts based on age and sex , that enrolled persons with a range of risk factors . Low risk was defined as serum cholesterol level less than 5.17 mmol/L ( < 200 mg/dL ) , blood pressure less than orequal to 120/80 mm Hg , and no current cigarette smoking . All persons with a history of diabetes , myocardial infa rct ion ( MI ) , or , in 3 of 5 cohorts , electrocardiogram ( ECG ) abnormalities , were excluded . SETTING AND PARTICIPANTS In 18 US cities , a total of 72144 men aged 35 through 39 years and 270671 men aged 40 through 57 years screened ( 1973 - 1975 ) for the Multiple Risk Factor Intervention Trial ( MRFIT ) ; in Chicago , a total of 10025 men aged 18 through 39 years , 7490 men aged 40 through 59 years , and 6229 women aged 40 through 59 years screened ( 1967 - 1973 ) for the Chicago Heart Association Detection Project in Industry ( CHA ) ( N = 366559 ) . MAIN OUTCOME MEASURES Cause-specific mortality during 16 ( MRFIT ) and 22 ( CHA ) years , relative risks ( RRs ) of death , and estimated greater life expectancy , comparing low-risk subcohorts vs others by age strata . RESULTS Low-risk persons comprised only 4.8 % to 9.9 % of the cohorts . All 5 low-risk groups experienced significantly and markedly lower CHD and cardiovascular disease death rates than those who had elevated cholesterol level , or blood pressure , or smoked . For example , age-adjusted RRs of CHD mortality ranged from 0.08 for CHA men aged 18 to 39 years to 0.23 for CHA men aged 40 through 59 years . The age-adjusted relative risks ( RRs ) for all cardiovascular disease mortality ranged from 0.15 for MRFIT men aged 35 through 39 years to 0.28 for CHA men aged 40 through 59 years . The age-adjusted RR for all-cause mortality rate ranged from 0.42 for CHA men aged 40 through 59 years to 0.60 for CHA women aged 40 through 59 years . Estimated greater life expectancy for low-risk groups ranged from 5.8 years for CHA women aged 40 through 59 years to 9.5 years for CHA men aged 18 through 39 years . CONCLUSIONS Based on these very large cohort studies , for individuals with favorable levels of cholesterol and blood pressure who do not smoke and do not have diabetes , MI , or ECG abnormalities , long-term mortality is much lower and longevity is much greater . A substantial increase in the proportion of the population at lifetime low risk could contribute decisively to ending the CHD epidemic Half of all postmenopausal women will have an osteoporosis-related fracture during their lives , including one quarter who will develop a vertebral deformity ( 1 ) and 15 % who will suffer a hip fracture ( 2 ) . Hip fractures are associated with high mortality rates and loss of independence ( 3 , 4 ) . Although many vertebral fractures are detected only incidentally on radiography , some cause severe pain , leading to 150 000 hospital admissions per year in persons older than 65 years of age , 161 000 physician office visits , and more than 5 million days of restricted activity in those 45 years of age or older ( 5 ) . Low bone density has been used to predict risk for fractures as well as to diagnose osteoporosis . Osteoporosis has been defined as a systemic skeletal disease characterized by low bone mass and microarchitectural deterioration of bone tissue , leading to enhanced bone fragility and a consequent increase in fracture risk ( 6 , 7 ) . This definition emphasizes that , in addition to bone mass , the structure of bone is an important factor in the pathogenesis of fractures . A World Health Organization working group ( 8) proposed that osteoporosis should be diagnosed in epidemiologic studies when  bone mineral density  is 2.5 SDs or more below the mean for healthy young adult women at the spine , hip , or wrist ( corresponding to a T-score 2.5 ) or when patients have a history of atraumatic fracture ( 9 ) . By the World Health Organization definition , up to 70 % of women older than 80 years of age have osteoporosis ( 10 ) . Age is also an important factor in the relationship between bone density and the absolute risk for fracture . Older women have a much higher fracture rate than younger women with the same bone density because of increasing risk from other factors , such as bone quality and tendency to fall ( 11 ) . Despite the high prevalence of osteoporosis and the effect of fractures on mortality , independence , and quality of life , it is not clear whether it is appropriate to screen asymptomatic postmenopausal women . Recent systematic review s and guidelines disagree about which women should be screened and when ( 12 - 20 ) . This disagreement reflects , in part , gaps in the evidence . For example , most guidelines recommend using risk factors to select patients for bone density testing , but because of inadequate data there is no consensus on which risk factors to use . As part of the U.S. Preventive Services Task Force up date of its 1996 recommendation ( 21 ) , we examined evidence on the benefits and harms of screening postmenopausal women for osteoporosis . Specifically , we addressed the role of risk factors in identifying high-risk women , techniques of bone density testing to identify fracture risks , effectiveness of treatment in reducing fracture risk , and harms of screening and treatment . Methods Additional methods used for this review , including determination of the quality of studies ( 22 ) , are detailed in Appendix Tables 1 , 2 , and 3 and in a separate report ( 23 ) . The analytic framework and key questions are detailed in the Appendix Figure . Relevant studies were identified from multiple search es of MEDLINE ( 1966 to May 2001 ) , HealthSTAR ( 1975 to May 2001 ) , and Cochrane data bases ; reference lists of systematic review s ; and experts . We also sent letters to manufacturers of bone density devices requesting additional information about the performance of their instruments , but we received no new data . Two review ers read each abstract to determine its eligibility . We included English- language abstract s that contained original data about postmenopausal women and osteoporosis and addressed screening or the effectiveness of risk factor assessment , bone density testing , or treatment . We considered screening to be the process of assessing postmenopausal women without known osteoporosis for risk of osteoporotic fractures by identification of risk factors , including low bone density . Postmenopausal women were those who had experienced surgical or natural menopause , regardless of age . Women with preexisting atraumatic fractures were not considered in the screening population because they had confirmed osteoporosis according to the World Health Organization definition . For studies of prediction , we selected articles that reported the relationship between risk factor assessment methods or bone density tests and bone density , bone loss , or fractures . We review ed studies of medications used for treatment and present results for bisphosphonates . We focused on r and omized , controlled trials of therapies reporting radiographically verified , nontraumatic fracture outcomes because fractures are a stronger measure of effectiveness than bone density . We excluded studies of primary prevention of osteoporosis , such as the role of nutrition , calcium consumption , and physical activity . We also excluded secondary causes of osteoporosis , such as corticosteroid use and certain chronic diseases , and studies that did not provide sufficient information to allow determination of the method for selecting patients and for analyzing data . Investigators read the full-text versions of the retrieved papers and reapplied the initial eligibility criteria . To assess the internal validity of individual studies , we applied a set of criteria developed by the third U.S. Preventive Services Task Force ( Appendix Table 1 ) ( 22 ) . In this paper , we highlight studies that are applicable to current practice st and ards , have high- quality internal validity ratings , and are most generalizable to the U.S. population of postmenopausal women under consideration for screening . We created an outcomes table to summarize the number of  hip and vertebral fractures  prevented based on age-specific prevalence rates and treatment effects obtained from results of the review ed studies . We conducted a sensitivity analysis to determine the influence of risk factors on the number needed to screen . This research was funded by the Agency for Healthcare Research and Quality under a contract to support the work of the U.S. Preventive Services Task Force . Agency staff and Task Force members participated in the initial design of the study and review ed interim analyses and the final manuscript . Additional reports were distributed for review to content experts and revised accordingly before preparation of this manuscript ( 23 , 24 ) . The authors are responsible for the content of the manuscript and the decision to su bmi t it for publication . Results Studies of Screening We identified no studies about the effectiveness of screening in reducing osteoporotic fractures . Without direct evidence from screening studies , recommendations about screening need to rely on evidence that risk factor assessment or bone density testing can adequately identify women who could ultimately benefit from treatment . Risk Factor Assessment Hundreds of studies report associations between risk factors and low bone density and fractures in postmenopausal women ( 24 ) . The most comprehensive study of risk factors in a U.S. population is the Study of Osteoporotic Fractures , a good- quality prospect i ve study of 9516 women 65 years of age and older ( 25 ) . In this study , 14 clinical risk factors were identified as significant predictors of hip fracture in multivariable models ( age ; maternal hip fracture ; no weight gain ; height ; poor self-rated health ; hyperthyroidism ; current use of benzodiazepines , anticonvulsants , or caffeine ; not walking for exercise ; lack of ambulation ; inability to rise from a chair ; poor scores on two measures of vision ; high resting pulse ; and any fracture since 50 years of age ) . The relative risk for hip fracture per decrease of 1 SD in calcaneal bone density was 1.6 ( 95 % CI , 1.3 to 1.9 ) . This was comparable to the magnitude of the relative risks of most of the other significant predictors in the model , which ranged from 1.2 to 2.0 . Women with at least 5 of the 14 risk factors had increased rates of hip fractures compared with those who had 0 to 2 risk factors at all levels of calcaneal bone density . To determine which risk factors could be important in women younger than 65 years of age , we review ed eight observational studies of risk factors and fractures of various types conducted in population s in which at least 50 % of participants were younger than 65 years of age . Table 1 lists risk factors that were statistically significant predictors for fractures in multivariable models ( 26 - 33 ) . These results could not be quantitatively combined because risk factors were defined differently in each study . Table 1 . Risk Factors for Fractures in Women 5065 Years of Age Results of risk factor studies have been used to assess risk in individuals . We identified 10 cross-sectional studies that described methods of determining risk for low bone density for individual women based on selected clinical risk factors ( Table 2 ) ( 34 - 43 ) . The most common method ologic limitations of these studies are lack of validation and lack of generalizability because of small numbers of patients or nonrepresentative patients . We also identified 8 studies of clinical risk factors to determine fracture risk ( Table 2 ) ( 44 - 51 ) . None of these studies received a good rating for internal validity . Four studies evaluated hip fracture outcomes , two evaluated vertebral fractures , and two evaluated all types of fractures . These studies described the association of risk factors with fractures known to have occurred already ( four casecontrol studies ) or how well they would predict fractures in the future ( four prospect i ve cohort studies ) . Table 2 . Studies of Risk Factor Assessment A recent study compared the performance of five clinical decision rules for bone density testing among 2365 postmenopausal women 45 years of age or older who were enrolled in a community-based study of osteoporosis in Canada ( 52 ) . These rules included guidelines from the National Osteoporosis Foundation ( 53 ) ; the Simple Calculated Osteoporosis Risk Estimation ( SCORE ) rule ( age , weight , ethnicity , estrogen use , Importance An abdominal aortic aneurysm ( AAA ) is typically defined as aortic enlargement with a diameter of 3.0 cm or larger . The prevalence of AAA has declined over the past 2 decades among screened men 65 years or older in various European countries . The current prevalence of AAA in the United States is unclear because of the low uptake of screening . Most AAAs are asymptomatic until they rupture . Although the risk for rupture varies greatly by aneurysm size , the associated risk for death with rupture is as high as 81 % . Objective To up date its 2014 recommendation , the USPSTF commissioned a review of the evidence on the effectiveness of 1-time and repeated screening for AAA , the associated harms of screening , and the benefits and harms of available treatments for small AAAs ( 3.0 - 5.4 cm in diameter ) identified through screening . Population This recommendation applies to asymptomatic adults 50 years or older . However , the r and omized trial evidence focuses almost entirely on men aged 65 to 75 years . Evidence Assessment Based on a review of the evidence , the USPSTF concludes with moderate certainty that screening for AAA in men aged 65 to 75 years who have ever smoked is of moderate net benefit . The USPSTF concludes with moderate certainty that screening for AAA in men aged 65 to 75 years who have never smoked is of small net benefit . The USPSTF concludes that the evidence is insufficient to determine the net benefit of screening for AAA in women aged 65 to 75 years who have ever smoked or have a family history of AAA . The USPSTF concludes with moderate certainty that the harms of screening for AAA in women aged 65 to 75 years who have never smoked and have no family history of AAA outweigh the benefits . Recommendations The USPSTF recommends 1-time screening for AAA with ultrasonography in men aged 65 to 75 years who have ever smoked . ( B recommendation ) The USPSTF recommends that clinicians selectively offer screening for AAA with ultrasonography in men aged 65 to 75 years who have never smoked rather than routinely screening all men in this group . ( C recommendation ) The USPSTF recommends against routine screening for  AAA  with ultrasonography in women who have never smoked and have no family history of AAA . ( D recommendation ) The USPSTF concludes that the current evidence is insufficient to assess the balance of benefits and harms of screening for AAA with ultrasonography in women aged 65 to 75 years who have ever smoked or have a family history of AAA . ( I statement ) Background Attenuation artifact remains a substantial limitation to confident interpretation of images and reduces laboratory efficiency by requiring comparison of stress and rest image sets . Attenuation-corrected stress-only imaging has the potential to ameliorate these limitations . Methods and Results Ten experienced nuclear cardiologists independently interpreted 90 stress-only electrocardiography (ECG)-gated technetium 99 m sestamibi images  in a sequential fashion : myocardial perfusion imaging ( MPI ) alone , MPI plus ECG-gated data , and attenuation-corrected MPI with ECG-gated data . Images were interpreted for diagnostic certainty ( normal , probably normal , equivocal , probably abnormal , abnormal , and perceived need for rest imaging ) . With stress MPI data alone , only 37 % of studies were interpreted as definitely normal or abnormal , with a very high perceived need for rest imaging ( 77 % ) . The addition of gated data did not alter the interpretations . However , attenuation-corrected data significantly increased the number of studies characterized as definitely normal or abnormal ( 84 % , P < 005 ) and significantly reduced the perceived need for rest imaging ( 43 % , P < .005 ) . These results were confirmed by use of a nonsequential consensus interpretation of three readers . Conclusion Attenuation correction applied to studies with stress-only Tc-99 m ECG-gated single photon emission computed tomography images significantly increases the ability to interpret studies as definitely normal or abnormal and reduces the need for rest imaging . These findings may improve laboratory efficiency and diagnostic accuracy Background & objectives : Morphological abnormalities in  12-lead electrocardiograms ( ECGs ) are seen in subgroups of healthy individuals like athletes and air-force personnel . As these population s may not truly represent healthy individuals , we assessed morphological abnormalities in ECG in healthy volunteers participating in phase I studies , who are screened to exclude associated conditions . Methods : ECGs from 62 phase I studies analyzed in a central ECG laboratory were pooled . A single drug-free baseline ECG from each subject was review ed by experienced cardiologists .  ECG intervals  were measured on five consecutive beats and morphological abnormalities identified using st and ard guidelines . Results : Morphological abnormalities were detected in 25.5 per cent of 3978 healthy volunteers ( 2495 males , 1483 females ; aged 18 - 76 yr ) ; the presence was higher in males ( 29.3 % vs. 19.2 % in females ; P<0.001 ) . Rhythm abnormalities were the commonest ( 11.5 % ) followed by conduction abnormalities ( 5.9 % ) , axis deviation ( 4 % ) , ST-T wave changes ( 3.1 % ) and chamber enlargement ( 1.4 % ) . Incomplete right bundle branch block ( RBBB ) , short PR interval and right ventricular hypertrophy were common in young subjects ( < 20 yr ) while atrial fibrillation , first degree atrioventricular block , complete RBBB and left anterior fascicular block were more prevalent in elderly subjects ( > 65 yr ) . Prolonged PR interval , RBBB and intraventricular conduction defects were more common in males while sinus tachycardia , short PR interval and non-specific T wave changes were more frequent in females . Interpretation & Conclusions : Morphological abnormalities in ECG are commonly seen in healthy volunteers participating in phase I studies ; and vary with age and gender . Further studies are required to determine whether these abnormalities persist or if some of these disappear on follow up Nicotine patches are commonly used by people who try to quit smoking . Because high doses of nicotine may increase heart rate and potentiate cardiac arrhythmia or ischemia , its use in patients with coronary artery disease was investigated . The objective was to assess the cardiovascular safety of nicotine patches in patients with coronary artery disease ( CAD ) who try to quit smoking . The study was conducted in a double-blind , placebo-controlled , r and omized fashion over a 2-week period . One hundred and six patients with CAD who wished to stop smoking and were taking part in a smoking cessation program were included . Fifty-two patients received nicotine patches ( Nicotinell ® ) and 54 received placebo patches .  The cardiovascular effects of nicotine patches were assessed by repeated ambulatory ECG monitoring ( AEM ) and exercise testing . There were no changes in the resting heart rate and in the systolic or diastolic blood pressure between the screening and the two phases of the study in both the Nicotinell and placebo groups . Repeated 48-hour AEM revealed that there were no significant changes in the number and duration of ischemic episodes in both groups . There was no change in the frequency of atrial or ventricular arrhythmias . Exercise duration and time to 1-mm ST-segment depression increased in both groups during the double-blind treatment phase . More patients in the Nicotinell group cl aim ed tobacco abstinence compared with the placebo group ( 27 % vs. 13 % ) . The use of nicotine patches did not cause aggravation of myocardial ischemia or arrhythmia in coronary patients and therefore can be used as a method to promote smoking cessation in this high-risk group
Evidence on harms was limited , but direct harms seemed minimal ( for resting ECG ) or small ( for exercise ECG ) .
BACKGROUND Coronary heart disease is the leading cause of death in adults .
Screening for abnormalities by using resting or exercise electrocardiography ( ECG ) might help identify persons who would benefit from interventions to reduce cardiovascular risk .
PURPOSE To up date the 2004 U.S. Preventive Services Task Force evidence review on screening for  resting or exercise ECG abnormalities in asymptomatic adults .