Effect of Nasal Continuous Positive Airway Pressure Treatment on Blood Pressure in Patients With Obstructive Sleep Apnea Rapid Risk Stratification for Obstructive Sleep Apnea, Based on Snoring Severity and Body Mass Index Repeating administration of Epworth Sleepiness Scale is clinically useful The occurrence of sleep-disordered breathing among middle-aged adults. Craniofacial profile in Asian and white subjects with obstructive sleep apnoea Usefulness of the Berlin Questionnaire to identify patients at high risk for obstructive sleep apnea: a population-based door-to-door study Neural network prediction of obstructive sleep apnea from clinical criteria. Controlled, prospective trial of psychosocial function before and after continuous positive airway pressure therapy A decision rule for diagnostic testing in obstructive sleep apnea. The use of clinical prediction formulas in the evaluation of obstructive sleep apnea. Reduction in motor vehicle collisions following treatment of sleep apnoea with nasal CPAP Prevalence of sleep-disordered breathing in women: effects of gender. Prospective study of the association between sleep-disordered breathing and hypertension. Physical examination: Mallampati score as an independent predictor of obstructive sleep apnea. Relationship Between Sleep Apnoea Syndrome, Snoring and Headaches Prevalence and risk factors of obstructive sleep apnea among middle-aged urban Indians: a community-based study. Predictive diagnostic value of clinical assessment and nonlaboratory monitoring system recordings in patients with symptoms suggestive of obstructive sleep apnea syndrome.
Background —There is increasing evidence that obstructive sleep apnea ( OSA ) is an independent risk factor for arterial hypertension . Because there are no controlled studies showing a substantial effect of nasal continuous positive airway pressure ( nCPAP ) therapy on hypertension in OSA , the impact of treatment on cardiovascular sequelae has been question ed altogether . Therefore , we studied the effect of nCPAP on arterial hypertension in patients with OSA . Methods and Results —Sixty consecutive patients with moderate to severe OSA were r and omly assigned to either effective or subtherapeutic nCPAP for 9 weeks on average . Nocturnal polysomnography and continuous noninvasive blood pressure recording  for 19 hours was performed before and with treatment . Thirty two patients , 16 in each group , completed the study . Apneas and hypopneas were reduced by ≈95 % and 50 % in the therapeutic and subtherapeutic groups , respectively . Mean arterial blood pressure decreased by 9.9±11.4 mm Hg with effective nCPAP treatment , whereas no relevant change occurred with subtherapeutic nCPAP ( P = 0.01 ) . Mean , diastolic , and systolic blood pressures all decreased significantly by ≈10 mm Hg , both at night and during the day . Conclusions —Effective nCPAP treatment in patients with moderate to severe OSA leads to a substantial reduction in both day and night arterial blood pressure . The fact that a 50 % reduction in the apnea-hypopnea index did not result in a decrease in blood pressure emphasizes the importance of highly effective treatment . The drop in mean blood pressure by 10 mm Hg would be predicted to reduce coronary heart disease event risk by 37 % and stroke risk by 56 % Objective It is unclear whether all snoring patients require polysomnography , and there are no highly sensitive clinical predictors of sleep apnea . Our objective was to develop a simple clinical screening test for OSA in snoring patients . Study Design Prospect i ve , IRB-approved study at a university sleep disorders center . Subjects and Methods In 211 patients undergoing polysomnography , snoring severity , Epworth sleepiness scale , body mass index , demographic , and sleep study data were collected . Receiver operating characteristic ( ROC ) analysis and Pearson correlation were used to develop a sensitive screening test for OSA . Results Snoring severity score ( SSS ) and BMI were the two most accurate predictors of OSA on the ROC curve . A bipartite threshold of SSS = 4 or BMI = 26 carried sensitivity of 97.4 % , specificity of 40 % , positive predictive value of 82.3 % , and negative predictive value of 84.2 % for moderate/severe OSA . Patients at high risk were those with BMI ≥32 ( 89 % PPV ) or SSS ≥7 ( 92 % PPV ) . Conclusions The statistic most predictive of OSA was snoring severity . Combining this with BMI yielded a highly sensitive screening test for moderate/severe OSA . This clinical assessment may be useful in risk-stratifying patients for polysomnography and therapy , facilitating deferred work-up in low-risk patients and expedited therapy in high-risk patients Purpose We aim ed to verify whether it is clinical ly useful to repeat the Epworth Sleepiness Scale ( ESS ) in individuals with suspected sleep-disordered breathing ( SDB ) . Methods In this cross-sectional , prospect i ve study , results of the repeated administration of the ESS were analyzed . In 929 consecutive patients ,  ESS  was obtained as usual in the laboratory routine , immediately before the sleep study ( ESS1 ) and was repeated in the morning , after the polysomnography ( ESS2 ) . ROC curve , classical psychometry , and item response theory ( IRT ) Rasch analysis were used to assess measurement properties of ESS . Results The ESS1 score was ( mean ± SD ) , 11 ± 5.1 , and the ESS2 , 13 ± 4.7 ( p < 0.001 ) . Change in ESS score is explained in multivariate analysis by age , but not by gender , educational level , change in Stanford Sleepiness Scale , symptoms of sleep disorder , or polysomnography results . Accuracy of an ESS score > 10 to predict apnea – hypopnea index ≥5 increased from 56 % ( ESS1 ) to 72 % ( ESS2 ) . IRT psychometric properties ( unidimensionality , invariance , local independence ) were maintained in ESS2 . Conclusions Repeating the administration of the Epworth Sleepiness Scale in a clinical setting increases its score and diagnostic accuracy and correlation with SDB variables , without changing the psychometric properties of the scale . This experiment indicates the clinical usefulness of repeating the ESS . The scale can be repeated at a negligible cost , before dismissing individual patients on the basis of a low ESS score , discontinuing a potentially lifesaving diagnostic and therapeutic process BACKGROUND Limited data have suggested that sleep-disordered breathing , a condition of repeated episodes of apnea and hypopnea during sleep , is prevalent among adults . Data from the Wisconsin Sleep Cohort Study , a longitudinal study of the natural history of cardiopulmonary disorders of sleep , were used to estimate the prevalence of undiagnosed sleep-disordered breathing among adults and address its importance to the public health . METHODS A r and om sample of 602 employed men and women 30 to 60 years old were studied by overnight polysomnography to determine the frequency of episodes of apnea and hypopnea per hour of sleep ( the apnea-hypopnea score ) . We measured the age- and sex-specific prevalence of sleep-disordered breathing in this group using three cutoff points for the apnea-hypopnea score ( > or = 5 , > or = 10 , and > or = 15 ) ; we used logistic regression to investigate risk factors . RESULTS The estimated prevalence of sleep-disordered breathing , defined as an apnea-hypopnea score of 5 or higher , was 9 percent for women and 24 percent for men . We estimated that 2 percent of women and 4 percent of men in the middle-aged work force meet the minimal diagnostic criteria for the sleep apnea syndrome ( an apnea-hypopnea score of 5 or higher and daytime hypersomnolence ) . Male sex and obesity were strongly associated with the presence of sleep-disordered breathing . Habitual snorers , both men and women , tended to have a higher prevalence of apnea-hypopnea scores of 15 or higher . CONCLUSIONS The prevalence of undiagnosed sleep-disordered breathing is high among men and is much higher than previously suspected among women . Undiagnosed sleep-disordered breathing is associated with daytime hypersomnolence Background : Clinical detection of structural narrowing of the upper airway may facilitate early recognition of obstructive sleep apnoea ( OSA ) . To determine whether the craniofacial profile predicts the presence of OSA , the upper airway and craniofacial structure of 239 consecutive patients ( 164 Asian and 75 white subjects ) referred to two sleep centres ( Hong Kong and Vancouver ) were prospect ively examined for suspected sleep disordered breathing . Methods : All subjects underwent a history and physical examination with measurements of anthropometric parameters and craniofacial structure including neck circumference , thyromental distance , thyromental angle , and Mallampati oropharyngeal score . OSA was defined as an apnoea-hypopnoea index ( AHI ) of ⩾5/hour on full overnight polysomnography . Results : Discriminant function analysis indicated that the Mallampati score ( F = 0.70 ) , thyromental angle ( F = 0.60 ) , neck circumference ( F = 0.54 ) , body mass index ( F = 0.53 ) , and age ( F = 0.53 ) were the best predictors of OSA . After controlling for ethnicity , body mass index and neck circumference , patients with OSA were older , had larger thyromental angles , and higher Mallampati scores than non-apnoeic subjects . These variables remained significantly different between OSA patients and controls across a range of cut-off values of AHI from 5 to 30/hour . Conclusions : A crowded posterior oropharynx and a steep thyromental plane predict OSA across two different ethnic groups and varying degrees of obesity Background The Berlin Question naire ( BQ ) is a useful tool to identify the high-risk group for obstructive sleep apnea ( OSA ) in the primary care sites or hospital , but the usefulness of the BQ to identify the high-risk group for OSA in the general population has not been evaluated . The purpose of our study was to develop the Korean version of the BQ ( KBQ ) and evaluate the usefulness of the BQ in identifying patients with OSA in the general population . Methods A total of 1,305 subjects were included in a population -based door-to-door cross-sectional study . For validation of the KBQ , an overnight polysomnography ( PSG ) was performed on 101 subjects who were r and omly selected considering their age , sex , and risk group classification at a controlled sleep laboratory . Results The KBQ showed a relatively good to excellent internal consistency ( Cronbach ’s α correlation 0.64–0.78 ) and test – retest reliability ( intraclass correlation 0.92 ) . The apnea – hypopnea index ( AHI ) was significantly correlated with the scores in each category and the total scores of the KBQ . In addition , high risk grouping based on the KBQ predicted an AHI ≥ 5 with a sensitivity of 0.69 and a specificity of 0.83 . According to the risk categorization based on the KBQ , 26.1 % subjects were in the high-risk group for OSA which was similar to the prevalence of OSA in a previous large epidemiological study using PSG in Korea . Conclusion This is the first study to confirm the usefulness of the BQ as a screening tool for OSA by prioritizing subjects at high risk for OSA in the general population STUDY OBJECTIVES Clinical prediction models for the diagnosis of  obstructive sleep apnea ( OSA ) have lacked the accuracy necessary to confidently replace polysomnography ( PSG ) . Artificial neural networks are computer programs that can be trained to predict outcomes based on experience . This study was conducted to test the hypothesis that a generalized regression neural network ( GRNN ) could accurately classify patients with OSA from clinical data . STUDY DESIGN Retrospective review . SETTING Regional sleep referral center . PATIENTS R and omly selected records of patients referred for possible OSA . MEASUREMENTS The neural network was trained using 23 clinical variables from 255 patients , and the predictive performance was evaluated using 150 other patients . RESULTS The prevalence of OSA  in this series of 405 patients ( 293 men and 112 women ) was 69 % . The trained GRNN had an accuracy of 91.3 % ( 95 % confidence interval [ CI ] , 86.8 to 95.8 ) . The sensitivity was 98.9 % for having OSA ( 95 % CI , 96.7 to 100 ) , and the specificity was 80 % ( 95 % CI , 70 to 90 ) . The positive predictive value that the patient would have OSA was 88.1 % ( 95 % CI , 81.8 to 94.4 ) , whereas the negative predictive value that the patient would not have OSA ( if so classified ) was 98 % ( 95 % CI , 94 to 100 ) . CONCLUSIONS Appropriately trained GRNN has the ability to accurately rule in OSA from clinical data , and GRNN did not misclassify patients with moderate to severe OSA . In this study , use of the neural network could have reduced the number of PSG studies performed . Prospect i ve validation of the neural network for the diagnosis of OSA is now required The aim of the study was to investigate psychosocial function before and after continuous positive airway pressure ( CPAP ) therapy  , and establish the determinants and consequences of objective CPAP use . In a prospect i ve , parallel-group study , changes in psychosocial scores were compared with conservative management or CPAP therapy for the sleep apnoea/hypopnoea syndrome ( SAHS ) . Patient/partner couples from the top ( CPAP treated , n=44 ) or bottom ( conservatively treated , n=25 ) of a CPAP waiting list rated marital satisfaction ( evaluation and nurturing relationship issues , communication and happiness ( ENRICH ) , behavioural question naire ) , health/functional status ( Short-Form-36 Health Survey , functional outcomes of sleep question naire ) and sleepiness ( Epworth sleepiness scale ) . Both groups ' ratings at baseline were completed while on conservative therapy . Baseline variables did not differ between groups . At follow-up , all seven summary psychosocial scores were statistically better in CPAP-treated patients , effect sizes ( ES ) ranging from moderate ( 0.5 sd : marital satisfaction ) to very large ( > 1.0 sd : patients health , functional status and sleepiness scores ) . Scores in conservatively-treated patients deteriorated to a small or moderate degree ( ES −0.2– −0.7 sd ) , while those in the CPAP-treated group improved to a larger degree ( 0.3–1.3 sd ) . Baseline polysomnographical and psychosocial scores , including marital satisfaction , did not predict objective CPAP use ( r<0.3 ) . CPAP use was modestly correlated ( r=0.3–0.6 ) with improvement in all psychosocial areas . Continuous positive airway pressure produced statistically and clinical ly significant psychosocial improvements , some of large magnitude , in psychosocial function . Determinants of usage were not identified , but benefits and usage were positively correlated Obstructive sleep apnea ( OSA ) is traditionally diagnosed using overnight polysomnography . Decision rules may provide an alternative to polysomnography . A consecutive series of patients referred to a tertiary sleep center underwent prospect i ve evaluation with the upper airway physical examination protocol , followed by determination of the respiratory disturbance index using a portable monitor .  Seventy-five patients were evaluated with the upper airway physical examination protocol .  Historic predictors included age , snoring , witnessed apneas , and hypertension . Physical examination-based predictors included body mass index , neck circumference , m and ibular protrusion , thyro-rami distance , sterno-mental distance , sterno-mental displacement , thyro-mental displacement , cricomental space , pharyngeal grade , Sampsoon-Young classification , and over-bite . A decision rule was developed using three predictors : a cricomental space of 1.5 cm or less , a pharyngeal grade of more than II , and the presence of overbite . In patients with all three predictors ( 17 % ) , the decision rule had a positive predictive value of 95 % ( 95 % confidence interval [ CI ] , 75 - 100 % ) and a negative predictive value of 49 % ( 95 % CI , 35 - 63 % ) . A cricomental space of more than 1.5 cm ( 27 % of patients ) excluded OSA ( negative predictive value of 100 % , 95 % CI , 75 - 100 % ) . Comparable performance was obtained in a validation sample of 50 patients referred for diagnostic testing . This decision rule provides a simple , reliable , and accurate method of identifying a subset patients with , and perhaps more importantly , without OSA STUDY OBJECTIVES To prospect ively study the utility of four clinical prediction models for either predicting the presence of obstructive sleep apnea ( OSA , apnea-hypopnea index [ AHI ] > or = 10/hour ) , or prioritizing patients for a split-night protocol ( AHI(3)20/hour ) . DESIGN All patients presenting for OSA evaluation completed a research question naire that included questions from previously developed clinical prediction models . The probability of sleep apnea for each patient for each model was calculated based upon the equation used in the model . Based upon two cutoffs of apnea-hypopnea index , 10 and 20 , the sensitivity , specificity , and positive predictive value were calculated . For the cutoffs AHI > or = 10 and > or = 20 , receiver operating characteristic curves were generated and the areas under the curves calculated . Comparisons of demographic information and symptom response were compared between patients with and without OSA , and men vs. women . SETTING Urban , accredited sleep disorders center . PATIENTS OR PARTICIPANTS All patients referred for evaluation of OSA who underwent polysomnography .  INTERVENTIONS N/A. RESULTS 370 patients ( 191 men , 179 women ) completed the study . 248 of the 370 ( 67 % ) patients had an AHI(3)10 ; 180 of the 370 ( 49 % ) had an AHI > or = 20 . For AHI > or = 10 , the sensitivities ranged from 76 to 96 % , specificities from 13%-54 % , positive predictive values from 69%-77 % using the probability cutoff of the original investigators ; the areas under the curve from 0.669 to 0.736 . For AHI(3)20 , the areas under the ROC curves ranged from 0.700 to 0.757 ; using cutoffs to maximized specificity , the sensitivities ranged from 33%-39 % , specificities from 87%-93 % , and positive predictive values from 72%-85 % . All the models performed better for men . CONCLUSIONS The clinical prediction models tested are not be sufficiently accurate to discriminate between patients with or without OSA but could be useful in prioritizing patients for split-night polysomnography BACKGROUND Patients with untreated obstructive sleep apnoea ( OSA ) have increased motor vehicle collisions ( MVCs ) . When successfully treated , they report improved driving and fewer mishaps , but there are few objective data to confirm this . A study was therefore undertaken to examine actual MVC data in a large group of patients with OSA before and after treatment with continuous positive airway pressure ( CPAP )  compared with a control group matched for age , sex , and type of driver 's licence ( commercial or non-commercial ) . METHODS Two hundred and ten patients of mean ( SD ) age 52 ( 11 ) years , body mass index ( BMI ) 35.5 ( 10 ) kg/m2 , apnoea/hypopnoea index ( AHI ) 54 ( 29 ) events/h were treated with CPAP for at least 3 years .  MVC records were obtained from the Ontario Ministry of Transportation ( MTO ) data base for patients and an equal number of r and omly selected control drivers . MVC rates were compared for 3 years before and after CPAP therapy for patients and for the corresponding time frames for controls . RESULTS Untreated patients with OSA had more MVCs than controls ( mean ( SD ) MVCs/driver/year 0.18 ( 0.29 ) v 0.06 ( 0.17 ) , p<0.001 ) . Following CPAP treatment the number of MVCs/driver/year fell to normal ( 0.06 ( 0.17 ) ) while , in controls , the MVC rate was unchanged over time ( 0.06 ( 0.17 ) v 0.07 ( 0.18 ) , p = NS ) . Thus , the change in MVCs over time between the groups was very significant ( change = –0.12 ( 95 % CI –0.17 to –0.06 ) , p<0.001 ) ) . The MVC rate in untreated patients ( n=27 ) remained high over time . Driving exposure was not different following CPAP . CONCLUSIONS The risk of MVCs due to OSA is removed when patients are treated with CPAP . As such , any restrictions on driving because of OSA could be safely removed after treatment The prevalence of sleep-disordered breathing has not been well studied in women , especially in terms of the effects of age , body mass index ( BMI ) , and menopause . We evaluated this question using a two-phase r and om sample from the general population . In Phase I , 12,219 women and 4,364 men ranging in age from 20 to 100 yr were interviewed ; and in Phase II , 1,000 women and 741 men of the Phase I subjects were selected for one night of sleep laboratory evaluation .  The results of our study indicated that , for clinical ly defined sleep apnea ( apnea/hypopnea index > or = 10 and daytime symptoms ) , men had a prevalence of 3.9 % and women 1.2 % , result ing in an overall ratio of sleep apnea for men to women of 3.3:1 ( p = 0.0006 ) . The prevalence of sleep apnea was quite low in premenopausal women ( 0.6 % ) as well as postmenopausal women with hormone replacement therapy ( HRT )  ( 0.5 % ) . Further , in these women the presence of sleep apnea appeared to be associated exclusively with obesity ( BMI > or = 32.3 kg/m2 ) . Postmenopausal women without HRT had a prevalence of sleep apnea that was significantly higher than the prevalence in premenopausal women with HRT ( 2.7 versus 0.6 % , p = 0.02 ) and was more similar to the prevalence in men ( 3.9 % ) , although it remained significantly less when controlling for age and BMI ( p = 0.001 ) . These data combined indicate that menopause is a significant risk factor for  sleep apnea in women and that hormone replacement appears to be associated with reduced risk BACKGROUND Sleep-disordered breathing is prevalent in the general population and has been linked to chronically elevated blood pressure in cross-sectional epidemiologic studies . We performed a prospect i ve , population -based study of the association between objective ly measured sleep-disordered breathing and hypertension ( defined as a laboratory-measured blood pressure of at least 140/90 mm Hg or the use of antihypertensive medications ) . METHODS We analyzed data on sleep-disordered breathing , blood pressure , habitus , and health history at base line and after four years of follow-up in 709 participants of the Wisconsin Sleep Cohort Study ( and after eight years of follow-up in the case of 184 of these participants ) . Participants were assessed overnight by 18-channel polysomnography for sleep-disordered breathing , as defined by the apnea-hypopnea index ( the number of episodes of apnea and hypopnea per hour of sleep ) . The odds ratios for the presence of hypertension at the four-year follow-up study according to the apnea-hypopnea index at base line were estimated after adjustment for base-line hypertension status , body-mass index , neck and waist circumference , age , sex , and weekly use of alcohol and cigarettes . RESULTS Relative to the reference category of an apnea-hypopnea index of 0 events per hour at base line , the odds ratios for the presence of hypertension at follow-up were 1.42 ( 95 percent confidence interval , 1.13 to 1.78 ) with an apnea-hypopnea index of 0.1 to 4.9 events per hour at base line as compared with none , 2.03 ( 95 percent confidence interval , 1.29 to 3.17 ) with an apnea-hypopnea index of 5.0 to 14.9 events per hour , and 2.89 ( 95 percent confidence interval , 1.46 to 5.64 ) with an apnea-hypopnea index of 15.0 or more events per hour . CONCLUSIONS We found a dose-response association between sleep-disordered breathing at base line and the presence of hypertension four years later that was independent of known confounding factors . The findings suggest that sleep-disordered breathing is likely to be a risk factor for hypertension and consequent cardiovascular morbidity in the general population STUDY OBJECTIVE To assess the clinical usefulness of the Mallampati score in patients with obstructive sleep apnea .  Mallampati scoring of the orophyarynx is a simple noninvasive method used to assess the difficulty of endotracheal intubation , but its clinical usefulness has not been vali date d in patients with sleep-disordered breathing . DESIGN Prospect i ve multivariate assessment of a predictor variable . SETTING The UCSF Sleep Disorders Center . PATIENTS OR PARTICIPANTS One hundred thirty-seven adult patients who were evaluated for possible obstructive sleep apnea . INTERVENTIONS Prospect i ve determination of the Mallampati score  , assessment of other variables for multivariate analysis , and subsequent overnight polysomnography .  MEASUREMENTS AND RESULTS The  Mallampati score  was an independent predictor of both the presence and severity of obstructive sleep apnea . On average , for every 1-point increase in the  Mallampati score , the odds of having obstructive sleep apnea ( apnea-hypopnea index > or = 5 ) increased more than 2-fold ( odds ratio [ per 1-point increase ] = 2.5 ; 95 % confidence interval : 1.2 - 5.0 ; p = .01 ) , and the apnea-hypopnea index increased by more than 5 events per hour ( coefficient = 5.2 ; 95 % confidence interval : 0.2 - 10 ; p = .04 ) . These results were independent of more than 30 variables that reflected airway anatomy , body habitus , symptoms , and medical history . CONCLUSION Our results indicate that Mallampati scoring is a useful part of the physical examination of patients prior to polysomnography . The independent association between  Mallampati score  and presence and severity of obstructive sleep apnea suggests that this scoring system will have practical value in clinical setting s and prospect i ve studies of sleep-disordered breathing There is still a controversy regarding the relationship between sleep apnoea syndrome and headaches , especially morning headaches . Our objectives were : ( i ) to compare the prevalence and the clinical data of  headaches in sleep apnoea syndrome ( SAS ) and control ( snorers ) groups defined by polysomnographic recording ; ( ii ) to analyse the clinical improvement of headaches with appropriate treatment ; and ( iii ) to correlate headaches with mood disorders , and nocturnal respiratory and architectural sleep parameters in order to underst and the underlying pathophysiological mechanisms . This is a prospect i ve study of 324 consecutive patients referred to our sleep centre for snoring . Of these , 312 patients who underwent sleep polysomnography were finally included . Patients and controls were interviewed about their medical past , headache history and clinical characteristics , their daytime sleepiness ( Epworth 's sleepiness scale ) and their mood disorders ( Zerssen 's scale ) . Follow-up of patients with headaches ( SAS and control groups ) , treated or not , was also assessed . According to our definition of SAS , patients were dissociated in SAS ( n = 164 ) and snorers ( n = 148 ) . Fifty-three SAS patients had headaches , of whom 58.5 % ( n = 30 ) suffered from morning headaches . However , there was no statistical difference between the two groups concerning the prevalence and the clinical characteristics of headaches . In addition , headaches and morning headaches were not correlated with nocturnal respiratory and architectural sleep parameters , nor with excessive daytime sleepiness , but were strongly correlated with mood disorders . In 36 SAS patients , headaches improved under treatment , but this was not statistically different from what was found among untreated snorers . Headaches and morning headaches are common in patients with SAS but may be considered as a non-specific symptom . The underlying mechanisms are not fully eluci date d but depression could play an important role . Despite this absence of specificity , the treatment of SAS , especially nasal continuous positive airway pressure , leads to an improvement in headaches in several cases BACKGROUND The epidemiology of obstructive sleep apnea ( OSA ) and obstructive sleep apnea syndrome ( OSAS ) is not well studied among Indians . We sought to determine the prevalence and risk factors of OSA in a middle-aged urban Indian population . METHODS We conducted a two-stage , cross-sectional , community-based study in four different socioeconomic zones of the South Delhi district , India , from April 2005 to June 2007 . In stage 1 , subjects of either gender aged 30 - 65 yrs were administered a question naire by door-to-door survey using systematic r and om sampling . Subjects that responded were classified as habitual and non-habitual snorers . In stage 2 , all the habitual and 10 % of r and omly selected non-habitual snorers were invited for overnight polysomnographic study . RESULTS Of the 2860 subjects approached , 2505 ( 88 % ) completed stage 1 . Habitual snoring was present in 452 ( 18 % ) subjects . In stage 2 , OSA defined as apnea-hypopnea index 5 was observed in 94 ( 32.4 % ) of 290 habitual snorers and 3 ( 4 % ) of 75 non-habitual snorers . Estimated population prevalence of OSA and OSAS was 9.3 % ( 95 % CI 8.2 - 10.5 % ) and 2.8 % ( 2.1 - 3.4 % ) respectively . On multivariable analysis , male gender ( adjusted odds ratio 3.8 [ 1.7 - 4.9 ] ) , body-mass index 25 kg/m(2 ) ( 4.1 [ 2.0 - 8.3 ] ) , and abdominal obesity ( 2.2 [ 1.9 - 5.3 ] ) were independently associated with the presence of OSA . A linear trend was observed in the prevalence of OSA across the socioeconomic strata . CONCLUSIONS OSA is a significant public health problem in the middle-aged Indian population across the socioeconomic spectrum . OSA is associated with some of the well known risk factors for cardiovascular disease UNLABELLED Obstructive sleep apnea syndrome ( OSA ) is of increasing importance because of its high prevalence and danger of morbidity to untreated patients . Diagnostic procedures need simplification . We evaluated the qualitative value of a stepwise diagnostic approach using clinical assessment and a home-based screening device according to current recommendations . METHODS We investigated 114 patients with symptoms suggestive of obstructive sleep apnea syndrome by means of their clinical features , question naire responses , four-channel nonlaboratory monitoring ( NLM ) and full polysomnography . Operative indices in the diagnosis of OSA were calculated . RESULTS A significant correlation ( r = 0.7 : p < 0.0001 ) was found between the oxygen desaturation index ( ODI ) and the respiratory disturbance index ( RDI ) . The calculation of the difference between ODI by NLM and RDI by polysomnography showed a lack of agreement . Home-based monitoring revealed a high sensitivity ( 94 % ) but a low specificity ( 41 % ) in diagnosing OSA . However , a combination of clinical features , question naires and pulse oximetry achieved a specificity of 92 % . CONCLUSION Home-based monitoring provides reasonable negative predictive values in the diagnosis of OSA syndrome in symptomatic patients . It therefore qualifies as a screening method . Combined with clinical features and question naires it provides high positive predictive values and may therefore prove useful in simplifying diagnostic procedures
IMPORTANCE Obstructive sleep apnea is a common disease , responsible for daytime sleepiness .
Prior to referring patients for definitive testing , the likelihood of obstructive sleep apnea should be established in the clinical examination .
OBJECTIVE To systematic ally review the clinical examination accuracy in diagnosing obstructive sleep apnea .