Principles of evidence based medicine Evidence-based mechanistic reasoning Speed of updating online evidence based point of care summaries: prospective cohort analysis Evidence-based medicine in the ICU: important advances and limitations. Computer-based teaching is as good as face to face lecture-based teaching of evidence based medicine: a randomised controlled trial Evidence-based medicine and the challenge of low back pain: where are we now? Computer-based teaching is as good as face to face lecture-based teaching of evidence based medicine: a randomized controlled trial
Health care professionals are increasingly required to base clinical decisions on the best available evidence . Evidence based medicine ( EBM ) is a systematic approach to clinical problem solving which allows the integration of the best available research evidence with clinical expertise and patient values . This paper explains the concept of EBM and introduces the five step EBM model  : formulation of answerable clinical questions ; search ing for evidence ; critical appraisal ; applicability of evidence ; evaluation of performance .  Subsequent articles will focus on the principles and critical appraisal of r and omised controlled trials , systematic review s , and meta-analyses , and provide a practical demonstration of the five step EBM model using a real life clinical scenario Systematic review s of high quality r and omized trials generally count as the ‘ best evidence ’ . However , well-conducted r and omized trials are sometimes unavailable , unfeasible , unethical or unnecessary . In such cases other forms of evidence must be considered . Many EBM proponents accept mechanistic reasoning ( ‘ pathophysiologic rationale ’ ) for generalizability , hypothesis generation , ruling out implausible hypotheses , and for supporting efficacy in the absence of other ‘ stronger ’ forms of evidence . Yet because mechanistic reasoning has often led us astray , most EBM proponents are justifiably sceptical about using mechanistic reasoning as evidence for efficacy . We suggest that the scepticism about the value of mechanistic reasoning should not extend to high quality mechanistic reasoning . Just as poor quality r and omized trials ( that are unblinded , underpowered or biased , that employ unconcealed allocation , or otherwise biased ) will not provide high quality evidence for efficacy , so poor quality mechanistic reasoning will be unreliable . In this theoretical exploration we suggest that mechanistic reasoning involving a not incomplete inferential chain and that takes potential complexity into account can and should be used as evidence of efficacy . We support our rules for mechanistic evidence with three examples Objective To evaluate the ability of  international point of care information summaries  to up date evidence relevant to medical practice . Design Prospect i ve cohort bibliometric analysis . Setting Top  five point of care information summaries ( Clinical Evidence , EBM Guidelines , eMedicine , Dynamed , UpTo Date ) ranked for coverage of medical conditions , editorial quality , and evidence based methodology . Main outcome measures From June 2009 to May 2010 we measured the incidence of research findings relating to potentially eligible newsworthy evidence . As sample s , we chose  systematic review s rated as relevant by international research networks ( such as , Evidence -Based Medicine , ACP Journal Club , and the Cochrane Collaboration ) . Every month we assessed whether each sample d review was cited in at least one chapter of the five summaries . The cumulative updating rate was analysed with Kaplan-Meier curves . Results From April to December 2009 , 128 review s were retrieved ; 53 % ( 68 ) from the literature surveillance journals and 47 % ( 60 ) from the Cochrane Library . At nine months , Dynamed had cited 87 % of the sample d review s , while the other summaries had cited less than 50 % . The updating speed of Dynamed clearly led the others . For instance , the hazard ratios for citations in EBM Guidelines and Clinical Evidence versus the top performer were 0.22 ( 95 % confidence interval 0.17 to 0.29 ) and 0.03 ( 0.01 to 0.05 ) . Conclusions Point of care information summaries include evidence relevant to practice at different speeds . A qualitative analysis of updating mechanisms is needed to determine whether greater speed corresponds to more appropriate incorporation of new information Evidence -based medicine ( EBM ) is an important strategy for assessing the vast amounts of published data and applying them appropriately to our patients . However , in intensive care medicine , there is a shortage of " gold st and ard " r and omized controlled trial evidence to support ( or not support ) therapeutic decisions . In addition , even when well-conducted r and omized trials have been performed , we are still left with unanswered questions . In the last 5 years , several clinical trials have yielded positive results with a number of interventions being shown to improve outcomes . Here , we will outline the limitations and advances of EBM in intensive care medicine , by discussing the key findings in the last few years from studies of therapeutic agents for ICU patients Background At postgraduate level evidence based medicine ( EBM ) is currently taught through tutor based lectures . Computer based sessions fit around doctors ' workloads , and st and ardise the quality of educational provision . There have been no r and omized controlled trials comparing computer based sessions with traditional lectures at postgraduate level within medicine . Methods This was a r and omised controlled trial involving six postgraduate education centres in the West Midl and s , U.K. Fifty five newly qualified foundation year one doctors ( U.S internship equivalent ) were r and omised to either computer based sessions or an equivalent lecture in EBM and systematic review s. The change from pre to post-intervention score was measured using a vali date d question naire assessing knowledge ( primary outcome ) and attitudes ( secondary outcome ) . Results Both groups were similar at baseline . Participants ' improvement in knowledge in the computer based group was equivalent to the lecture based group ( gain in score : 2.1 [ S.D = 2.0 ] versus 1.9 [ S.D = 2.4 ] ; ANCOVA p = 0.078 ) . Attitudinal gains were similar in both groups . Conclusion On the basis of our findings we feel computer based teaching and learning is as effective as typical lecture based teaching sessions for educating postgraduates in EBM and systematic review Low  back pain  has long been described as a challenge for both primary care physicians and specialists . Management of  low back pain  has also been criticized as frequently arbitrary , inappropriate , or ineffective . Contributing factors have been an inadequate evidence base and a need for more rigorous appraisal s of the available literature . Evidence -based medicine , an approach to clinical problem solving , is predicated on the premise that high- quality health care will result from practice s consistent with the best evidence . In contrast to the traditional medical paradigm that placed a heavy reliance on expert opinion , authority , and un systematic clinical observations , evidence -based medicine emphasizes the need for rigorous critical appraisal s of the scientific literature to inform medical decision making . Evidence -based medicine places strong weight on the requirement for valid studies , particularly r and omized controlled trials , to appropriately evaluate the effectiveness of health care interventions . Because of the rapidly increasing volume of medical literature , however , most clinicians are unable to keep up-to- date with all the new data . Two types of preprocessed evidence that can aid busy clinicians in medical decision making are systematic review s and evidence -based clinical practice guidelines . Like primary studies , systematic review s and clinical practice guidelines must adhere to high method ologic st and ards to reduce error and bias . As in other areas of medicine , the approach to the management of low back pain has been positively affected by the availability of more clinical trials and better use of critical appraisal techniques to evaluate and apply research findings . In addition to more rigorous primary studies , an increasing number of high- quality systematic review s and evidence -based clinical practice guidelines for low back pain are also available . Although some research gaps and method ologic shortcomings persist , the richer evidence base has greatly improved our underst and ing of what does and does not work for low back pain . Despite these advances , the best available evidence often does not inform everyday clinical decisions for low back pain . Nonetheless , there is widespread agreement that adherence to evidence -based practice will help improve low back pain patient outcomes and reduce arbitrary variations in care . This article review s basic principles of evidence -based medicine , discusses evidence -based medicine in the context of low back pain management , and summarizes some useful evidence -based medicine re sources Background : Assessing in undergraduate medical education the educational effectiveness of a short computer-based session , integrating a lecturer 's video with a st and ardized structure , for evidence based medicine ( EBM ) teaching , compared to a lecture-based teaching session of similar structure and duration . Method : A concealed , r and omized controlled trial of computer based session versus lecture of equal duration ( 40 minutes ) and identical content in EBM and systematic review s. The study was based at the Medical School , University of Birmingham , UK involving one hundred and seventynine year one medical students . The main outcome measures were change from pre to post-intervention score measured using a vali date d question naire assessing knowledge ( primary outcome ) and attitudes ( secondary outcome ) . Results : Participants ’ improvement in knowledge in the computer based group was equivalent to the lecture based group ( gain in score : 0.8 [ S.D = 3.2 ] versus 1.3 [ S.D = 2.4 ] ; p = 0.24 ) . Attitudinal gains were similar in both groups . Conclusion : Computer based teaching and typical lecture sessions have similar educational gains
In addition , numerous trials have shown no difference regarding the most commonly studied endpoint : frequency of symptoms .
In 5 trials with participants under heavy acute physical stress ( 3 with marathon runners )  , vitamin C  reduced the incidence of colds by 52 % ( 95 % CI : 36 % to 65 % ) , but there is no evidence that vitamin C prevents colds in the general population .
Proponents of evidence -based medicine ( EBM ) emphasize that conclusions about medical interventions should be based on controlled trials with clinical ly relevant outcomes , so that the greatest weight should be given to the systematic review s of the trials .
So far , therapeutic supplementation has not been shown to be effective .