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 The evidence house: how to build an inclusive base for complementary medicine. A cluster randomized controlled trial to evaluate the effectiveness of the clinically integrated RHL evidence -based medicine course Evaluating the teaching of evidence-based medicine. Methodology and reporting of randomised controlled trials. The capture-mark-recapture technique can be used as a stopping rule when searching in systematic reviews. Bias in Systematic Reviews? Efficiency and Contribution of Strategies for Finding Randomized Controlled Trials: A Case Study from a Systematic Review on Therapeutic Interventions of Chronic Depression Evaluating the impact of an evidence-based medicine educational intervention on primary care doctors' attitudes, knowledge and clinical behaviour: a controlled trial and before and after study. Teaching evidence-based medicine skills can change practice in a community hospital Good intentions and received wisdom are not enough Reports of clinical trials should begin and end with up-to-date systematic reviews of other relevant evidence: a status report. Some Observations on “Observational” Research Yoga and Mindfulness as Therapeutic Interventions for Stroke Rehabilitation: A Systematic Review Effectiveness of an e-learning course in evidence-based medicine for foundation (internship) training Critical appraisal skills of family physicians in Ontario, Canada The Cochrane Collaboration.
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 We all want good evidence available when making medical decisions . Evidence , however , comes in a variety of forms and purpose s , and what may be good for one purpose may not be good for another . The term “ evidence -based medicine ” ( EBM ) has become almost a cliche in recent years , being used as a synonym for “ good ” or “ scientific , ” both to support and refute the value of complementary medicine practice s.1 But EBM takes a narrow view of what constitutes “ good ” evidence , and it excludes important qualitative and observational information about the use and benefits of complementary medicine . The key idea of EBM is a “ hierarchy of evidence ” ( figure 1 ) . In this hierarchy , information from systematic review s of r and omized controlled trials is the “ best ” evidence , followed by individual r and omized controlled trials , then by nonr and omized trials , observational studies , and finally case-series.2 When the evidence of what type of medicine works and what type does not is synthesized , the type of emphasis is at the top of the pyramid , and the evidence that is considered inferior is at the lower levels . Clinical experiments that isolate a causal and additive link between a specific intervention and a specific clinical outcome are seen as the “ gold st and ard ” in this evidence model . Figure 1 The traditional hierarchy of evidence is narrow As most clinicians know , the reasons that patients recover from illness are complex and synergistic , and many can not simply be isolated in controlled environments . The best evidence under these circumstances may be observational data from clinical practice that can estimate the likelihood of a patient 's recovery in a realistic context .3 In addition , patient 's illnesses are complex physical , psychological , and social experiences that can not be reduced to single , objective measures .4 In some cases , the most valuable information for a clinical decision is a highly subjective judgment about life quality . This personal experience of illness might be captured only through qualitative research , not using question naires or results of blood tests.5 The “ best ” evidence under these circumstances may be the meaning that patients give to their illness and recovery . At other times , the “ best ” evidence comes from laboratory studies . The discovery that St John 's wort can reduce blood levels of immunosuppressive drugs , for example , is the most crucial evidence when making decisions about its use in patients taking immunosuppressive medications.6 Findings of controlled trials often do not reveal such drug interactions . Arranging types of evidence in a “ hierarchy ” obscures the fact that sometimes the best evidence is not objective , not additive , and not clinical .7 In the place of an evidence hierarchy , I suggest we build an “ evidence house ” with “ rooms ” for different types of information and purpose s ( figure 2 ) . The rooms on the left side of the house contain types of information that seek out causal attributions and mechanisms of action . One such room is for laboratory research , which forms a foundation of underst and ing of mechanisms and causal links on which controlled clinical research can build . In the case of homeopathy or prayer , for example , r and omized controlled trial data seem to point us in an illogical direction , eg , that pills with no active ingredients have specific effects.8 Other rooms on the left side of the house are for r and omized controlled trials and systematic review s , which attempt to verify the suspected links between specific interventions and specific outcomes . Figure 2 The evidence house affords greater accessibility to important information If confined to the left side of the evidence house , however , physicians will never obtain information about the relevance of medicine for patients , what happens in the actual world of clinical practice , or the generalizability of an intervention in our health care delivery system . Information about relevance and utility of practice , both proven and unproven , is available in rooms on the right side of the house . The evidence house has something for everyone . Regulatory agencies and those interested in the approval of new treatments are most interested in the rooms on the left side . They want data from r and omized controlled trials and systematic review s rather than findings from observational research , yet the need for alternative approaches to treatment is evident.9 Other stakeholders in the health care system are more interested in information from the right side of the house . Health care practitioners often want to know the anticipated effects of an intervention in the clinical practice setting . Those paying for care are generally more interested in health services research . Patients are intensely interested in stories and detailed descriptions of cases similar to their own.10 If re sources are disproportionately invested in certain rooms of the house to the neglect of others , it is not possible to obtain the evidence needed for full public participation in clinical decisions . A livable house should not have an elaborate kitchen and no bathroom . Each has different functions and all need to be high quality . Complementary and alternative medicine helps us think about who will live in the evidence house and how it should be constructed . The public is the architect , driving the interest in complementary medicine . They seek holistic and preventive care , safer treatments for chronic illness , and more participation in health care decisions.11 As patient advocates , physicians must help them find a seat at the research table , so it is possible to build an evidence house where everyone can live Background and objectives Evidence -based health care requires clinicians to engage with use of evidence in decision-making at the workplace . A learner-centred , problem-based course that integrates e-learning in the clinical setting has been developed for application in obstetrics and gynaecology units . The course content uses the WHO reproductive health library ( RHL ) as the re source for systematic review s. This project aims to evaluate a clinical ly integrated teaching programme for incorporation of evidence provided through the WHO RHL . The hypothesis is that the RHL-EBM ( clinical ly integrated e-learning ) course will improve participants ' knowledge , skills and attitudes , as well as institutional practice and educational environment , as compared to the use of st and ard postgraduate educational re sources for EBM teaching that are not clinical ly integrated . Methods The study will be a multicentre , cluster r and omized controlled trial , carried out in seven countries ( Argentina , Brazil , Democratic Republic of Congo , India , Philippines , South Africa , Thail and ) , involving 50 - 60 obstetrics and gynaecology teaching units . The trial will be carried out on postgraduate trainees in the first two years of their training . In the intervention group , trainees will receive the RHL-EBM course .  The course consists of five modules , each comprising self-directed e-learning components and clinical ly related activities , assignments and assessment s , coordinated between the facilitator and the postgraduate trainee . The course will take about 12 weeks , with assessment s taking place pre-course and 4 weeks post-course . In the control group , trainees will receive electronic , self-directed EBM-teaching material s. All data collection will be online . The primary outcome measures are gain in EBM knowledge , change in attitudes towards EBM and competencies in EBM measured by multiple choice questions ( MCQs ) and a skills-assessing question niare administered eletronically . These questions have been developed by using questions from vali date d question naires and adapting them to the current course . Secondary outcome measure will be educational environment towards EBM which will be assessed by a specifically developed question naire . Expected outcomes The trial will determine whether the RHL EBM ( clinical ly integrated e-leraning ) course will increase knowledge , skills and attitudes towards EBM and improve the educational environment as compared to st and ard teaching that is not clinical ly integrated . If effective , the RHL-EBM course can be implemented in teaching institutions worldwide in both , low- and middle income countries as well as industrialized setting s. The results will have a broader impact than just EBM training because if the approach is successful then the same educational strategy can be used to target other priority clinical and method ological areas .Trial Registration AN INCREASING NUMBER OF MEDICAL SCHOOLS AND residency programs are instituting curricula for teaching the principles and practice of evidence based medicine ( EBM ) . For example , 95 % of US internal medicine residency programs have journal clubs and 37 % of US and Canadian internal medicine residencies have time dedicated for EBM . Curricula based on EBM are increasingly popular in residency programs in other specialties , including family medicine , pediatrics , obstetrics/ gynecology , and surgery . Despite the widespread teaching of EBM , however , most of what is known about the outcomes of evidence -based curricula relies on observational data . Although evaluation of the quality of research evidence is a core competency of EBM , the quantity and quality of the evidence for effectively teaching EBM are poor . Ironically , if one were to develop guidelines for how to teach EBM based on these results , they would be based on the lowest level of evidence . There are several reasons why the quality of the evidence for teaching EBM is so weak . Many of these problems are related to the limitations in educational research in general . First , quantitative research methods may be inadequate to capture the complexity of an educational system . Second , students and residents change frequently , making it difficult to retain a consistent sample . Third , the time allotted for a given intervention may be brief in the context of the overall medical curriculum . Fourth , educational institutions may be hesitant to pay students as research participants or to allocate them to unproved educational interventions . Fifth , because most educational interventions are unique to specific institutions , assessment of their effectiveness is usually limited by small sample sizes . Furthermore , even if such interventions could be instituted across multiple institutions , the problems of st and ardization and cointervention would be particularly challenging . Sixth , perhaps because they are simplest to measure , the most frequently reported outcomes are subjective variables such as satisfaction or self-reported changes in attitudes or knowledge , rather than more important assessment s of objective ly measured clinical skills or improved patient outcomes . Finally , granting agencies do not give priority to educational investigations , making it difficult to undertake definitive multicenter studies . Educators who have struggled to evaluate educational interventions will find these issues all too familiar . With the increasing prevalence of EBM teaching , however , high quality evidence is more important than ever . Assessment of EBM teaching has also presented some unique problems . For instance , we originally defined evidence -based practice in terms of 4 basic competencies : ( 1 ) recognition of a patient problem and construction of a structured clinical question ; ( 2 ) ability to efficiently and effectively search the medical literature to retrieve the best available evidence to answer the clinical question ; ( 3 ) critical appraisal of the evidence ; and ( 4 ) integration of the evidence with all aspects of individual patient decision making to determine the best clinical care for the patient . Although these 4 skills were the most commonly reported curricular objectives in 99 internal medicine residencies that teach EBM , almost all the research on EBM education has focused exclusively on the third item : teaching critical appraisal skills . Examining this literature may yield useful insights into the difficulties of EBM educational research . Since critical appraisal skills involve the ability to differentiate strong from weak research methods , one might expect that this research would be of relatively high quality . In fact , most of these studies are method ologically weak . Using broad criteria to identify any reports of a graduate ( residency ) EBM curricula , Green identified 18 reports published between 1980 and 1997 . Of these , 72 % used a traditional journal club format to teach critical appraisal skills . Only 7 of the 18 studies evaluated the effectiveness of their intervention . Five of these 7 studies compared intervention with control ( only 1 with r and omized design ) ; only 2 of 7 studies used any blinding . Of these 5 controlled studies , 2 used a vali date d outcome measure to evaluate  critical appraisal skills .  Measurement of behavioral change relied on self-report in all 5 studies , and none examined patient outcomes . Most reports did not evaluate their A systematic review of the literature will fail to provide information needed for evidence -based medicine ( EBM ) if the design , execution and reporting of individual trials do not adhere to strict guidelines . Experience gained while conducting systematic literature review s have revealed serious shortcomings in current literature . These limitations pertain to r and omisation , blinding , outcome assessment s and data reporting . The principles related to these issues are discussed with solutions and improvements provided OBJECTIVE Research ers have no empirically based search stopping rule when looking for potentially relevant articles for inclusion in systematic review s. We tested a stopping strategy based on capture-mark-recapture ( CMR ; i.e. , the Horizon Estimate ) statistical modeling to estimate the total number of articles in the domain of clinical decision support tools for osteoporosis disease management using four large bibliographic data bases ( Medline , EMBASE , CINAHL , and EBM review s ) . STUDY DESIGN AND SETTING Retrospective evaluation of the Horizon Estimate using a systematic review of r and omized controlled trials ( RCTs ) at two levels of article screening : title and abstract ( 1,246 potentially relevant articles ) and full text ( 42 potentially relevant articles ) . RESULTS The CMR model suggests that the total number of potential articles was 1,838 for the first level of screening , and 49 for the full-text level . The four data bases provided 68 % of known articles for the first level of screening and 81 % for full-text screening . CONCLUSIONS The CMR technique can be used in systematic review s to estimate the closeness to capturing the total body of literature on a given topic . More studies are needed to objective ly determine the usefulness of Horizon Estimates as a stopping rule strategy for systematic review search ing At an orthodontic meeting in recent years , a colleague recounted to me that when a presenter had finished their presentation on a systematic review , the person beside leaned over and said to my colleague ‘ not another systematic review where it ’s not possible to draw any firm conclusions ’ . So an element of frustration was clear based on the screening of a large volume of evidence to arrive at such a low point for a conclusion . This , however , is now a familiar outcome for many orthodontic systematic review s. In this short editorial , I have attempted to give a brief outline of the proposed benefits of systematic review s but more importantly , to highlight , some issues we all need to bear in mind in their regard . The increasing focus on evidence -based healthcare , including orthodontics , has shunned the narrative review and spawned the systematic review . Aim ing to identify , evaluate and summarize the findings of all relevant studies on a specific topic , its exacting systematic approach should minimize bias and provide conclusions based on reliable findings . Meta-analyses of r and omized clinical trials with low risk of bias are considered the highest level of evidence available for evaluating the effects of an intervention . Systematic review s are also important tools in setting the research agenda via their recommendations for future research and authors can alert research ers to the most pertinent outcomes in clinical practice . But systematic review s like any other study type are not without their variability , both in dentistry in general and specifically in orthodontics . Large differences have also been observed in the quality of reporting of several characteristics between Cochrane and non-Cochrane systematic review s. A key question that must be asked when looking at all Cochrane review s is whether the review has been undertaken in a way to avoid bias and whether the data and results from the included studies are valid . Conclusions may be distorted if bias is introduced to the review process at any stage . For example , incomplete search ing for all relevant studies may lead to publication bias ; there is strong association between publication and studies reporting significant or positive findings in medicine and also within orthodontics . With regard to studies included within the review , these need to be assessed to ensure that they are undertaken and reported in a manner that is free of bias ( systematic error ) . Outcome reporting bias ( ORB ) may also be relevant , e.g. in a study identified as relevant to a review , where data exist on the outcome of interest but only selected findings have been given based on the results . Although systematic review s have emphasized ‘ assessment of method ological quality ’ of included studies , the Cochrane h and book recommends a focus on ‘ risk of bias assessment ’ instead . The justifications are four-fold : it targets whether the results of included studies should be credible ; despite being carried out to the highest st and ards , a study may have risk of bias due to , e.g. impracticality/impossibility of blinding of participants / study personnel ; some quality markers , e.g. a power calculation is unlikely to directly affect risk of bias ; it overcomes ambiguity between quality of reporting and quality of the underlying research Background Identifying all existing evidence is a crucial aspect in conducting systematic review s. Since the retrieval of electronic data base search es alone is limited , guidelines recommend the use of additional search strategies . The aim of this investigation was to assess the efficiency and contribution of additional search strategies for identifying r and omized controlled trials in conducting a systematic review on interventions after performing a sensitive electronic data base search . Design and Methods Seven electronic data bases , 3 journals and 11 systematic review s were search ed . All first authors of the included studies were contacted ; citation tracking and a search in clinical trial registers were performed . A priori defined evaluation criteria were calculated for each search strategy . Results A total of 358 full-text articles were identified ; 50 studies were included in the systematic review , wherefrom 84.0 % ( 42 ) were acquired by the sensitive electronic data base search and 16.0 % ( 8) through additional search strategies . Screening reference lists of related systematic review s was the most beneficial additional search strategy , with an efficiency of 31.3 % ( 5 ) and a contribution of 10.0 % ( 5/50 ) , whereas h and - search ing and author contacts contributed two and one additional studies , respectively . Citation tracking and search ing clinical trial registers did not lead to any further inclusion of primary studies . Conclusions Based on our findings , h and - search ing contents of relevant journals and screening reference lists of related systematic review s may be helpful additional strategies to identify an extensive body of evidence . In case of limited re sources , a sensitive electronic data base search may constitute an appropriate alternative for identifying relevant trials . Significance for public health Systematic review s provide the strongest form of evidence synthesis for therapeutic interventions and are of high relevance for decision makers in public health . Preparing high quality systematic review s can be very time-consuming since all existing evidence should be identified , but the retrieval of electronic data base search es is limited and therefore additional search strategies are recommended . However , the time needed for conducting full systematic review s does often not address the need for urgent evidence . Thus , priorities of summarizing all available evidence and providing fast evidence -based recommendations may conflict . So far , no consensus exists regarding which additional search strategies are beneficial and sparsely time-consuming for conducting systematic review s. We examined the efficiency and contribution of additional search strategies performed after a sensitive electronic data base search . Our results provide highly relevant information for research ers conducting systematic review s in various fields of public health research and for establishing guidelines for conducting rapid review RATIONALE , AIMS AND OBJECTIVES Traditional continuing medical education programmes that offer passive learning have been shown to be poorly effective at changing doctors ' clinical behaviour . A multifaceted evidence -based medicine ( EBM ) intervention was conducted at the largest health maintenance organization ( HMO ) in Israel , attempting to facilitate a change in doctors ' attitudes , knowledge and clinical behaviour . No study thus far has examined the association between the teaching of EBM principles and doctors ' clinical behaviour . This study evaluated the intervention programme through a controlled trial and before and after study . The objective of the evaluation is binary : first , to examine the impact of an educational intervention on  family doctors ' test ordering performance and drug utilization by their patients ; and second , to assess the impact of the intervention on attitudes towards evidence -based practice and knowledge . METHODS Controlled trial and before and after study . Primary care clinics comprising similar patient characteristics were r and omly allocated to the experimental or to the control group . Doctors in the experimental group participated in an EBM educational intervention , while the control group did not take part in the intervention . Clinicians ' test ordering performance and their patients ' drug utilization were derived from the HMO 's data base before intervention , after workshops and after intervention . Participants in the controlled trial consisted of 75 doctors and their 106 349 patients . The before and after study evaluated intervention doctors ' ( n = 70 ) EBM attitudes and knowledge through a vali date d question naire before and after workshops . RESULTS EBM workshops enhanced intervention doctors ' EBM knowledge scores from 22.4/100 before workshops to 40.8/100 after workshops ( P = 0.000 ) . Doctors improved their ability to formulate clinical questions while enhancing their search strategy using Medline . In a linear regression model , two covariates , specialization ( B = 12.59 ; P = 0.001 ) and habitually reading medical journals ( B = 6.45 ; P = 0.052 ) , best explained the variance in doctors ' EBM knowledge scores , while controlling for pre-intervention scores ( R(2 ) = 0.569 ; P = 0.000 ) . Results from the controlled trial indicated that no statistically significant differences were found between intervention and control doctors ' test ordering performances , and their patients ' drug utilization . CONCLUSIONS The results of the study suggest that the intervention positively influenced attitudes and knowledge ; however , no statistically significant impact was found on doctors ' test ordering performance and on their patients ' drug utilization . The intervention 's inability to change doctors ' clinical behaviour might be remedied by improving future interventions through adding additional facets to the educational intervention , such as social marketing techniques and personal feedback . A longer and more extensive intervention might be more effective but is extremely difficult to execute as we found in this study . Future larger-scale interventions must incorporate the intervention into the routines of the organization , thus minimizing barriers towards EBM implementation OBJECTIVES : Several studies have evaluated whether evidence -based medicine ( EBM ) training courses can improve skills such as literature search ing and critical appraisal but to date , few data exist on whether teaching EBM skills and providing evidence -based re sources result in change in behavior or clinical outcomes . This study was conducted to evaluate whether a multifaceted EBM intervention consisting of teaching EBM skills and provision of electronic evidence re sources changed clinical practice . DESIGN : Before/after study . SETTING : The medical inpatient units at a district general hospital . PARTICIPANTS : Thirty-five attending physicians and 12 medicine residents . INTERVENTION : A multicomponent EBM intervention was provided including an EBM training course of seven 1-hour sessions , an EBM syllabus and textbook , and provision of evidence -based re sources on the hospital network . MEASUREMENTS AND MAIN RESULTS : The primary outcome of the study was the quality of evidence in support of therapies initiated for the primary diagnoses in 483 consecutive patients admitted during the month before and the month after the intervention . Patients admitted after implementation of the EBM intervention were significantly more likely to receive therapies proven to be beneficial in r and omized controlled trials ( 62 % vs 49 % ; P=.016 ) . Of these trial-proven therapies , those offered after the EBM intervention were significantly more likely to be based on high- quality r and omized controlled trials ( 95 % vs 87 % ; P=.023 ) . CONCLUSIONS : A multifaceted intervention design ed to teach and support EBM significantly improved evidence -based practice patterns in a district general hospital There is a common view among social and public health scientists that there is an evidence -based medicine ( EBM ) juggernaut , a powerful , naive , and overweening attempt to impose an inappropriately narrow and medical model of experimentation onto a complex social world . We have both frequently come across hostility among social scientists , and public health or health promotion practitioners or theorists , to attempts to apply EBM principles ( for example , systematic review s or experimental design s ) in social or public health setting s ( for example , sex education in schools , health promotion campaigns , or community development1 ) . We believe such hostility to be misplaced , and to be based on a number of misconceptions . The first misconception is that systematic review s and experimental design s have a wholly biomedical provenance . As Ann Oakley has pointed out , the use of experimental design s was well established in United States by the 1930s , and from the early 1960s to early 1980s there were many r and omised experiments for evaluating public policy interventions in United States , these being considered the optimum design . Much of the early literature on experimental design s ( including blinding ) came from the social sciences , as a response to the perceived need to be able to make valid causal inferences.2 The second misconception is that the “ real world ” is too complex , messy , OBJECTIVE Scientific and ethical justification for new clinical trials requires them to have been design ed in the light of scientifically defensible assessment s of relevant previous research . Reliable interpretation of the results of new clinical trials entails setting them in the context of up date s of the review s upon which they were deemed scientifically and ethically justifiable . We have shown previously that most reports of r and omized trials published in five general medical journals in May 1997 and in May 2001 failed to set their results in the context of the findings from similar research . In the current study , we assess whether there had been progress in this respect in 2005 and also investigate the extent to which reports begin by referring to systematic review s providing the justification for the new research reported . DESIGN Assessment of the Introduction and Discussion sections in all reports of r and omized trials published during May 2005 in five general medical journals . SETTING Reports of r and omized trials in five general medical journals . PARTICIPANTS Annals of Internal Medicine , BMJ , JAMA , Lancet and New Engl and Journal of Medicine . INTERVENTIONS None . MAIN OUTCOME MEASURES The inclusion or mention of one or more systematic review s in the Introduction or Discussion section of each report assessed . RESULTS We found 18 reports of r and omized trials . The Introduction sections referred to systematic review s in five ( 27 % ) of these reports . None of the discussion sections of the 15 reports of trials that were not the first published trials to address the question studied placed the results of the new trial in the context of an up date d systematic review of other research . Although reference was made to relevant systematic review s in five of these 15 reports , there was no integration - quantitative or qualitative - of the results of the new trials in an up date of these review s. In the remaining ten reports there was no evidence that any systematic attempt had been made to set the new results in the context of previous trials . CONCLUSIONS There is no evidence of progress between 1997 and 2005 in the proportion of reports of trials published in general medical journals which discussed new results within the context of up-to- date systematic review s of relevant evidence from other controlled trials . Although the proportion of trials referring to systematic review s in Discussion sections has increased , the majority of reports continued to fail even to do this . Similarly , most research ers appear not to have considered a systematic review when design ing their trial . Research ers and journal editors do a disservice to the interests of the public and others involved in healthcare decision-making by acquiescing in this situation Evidence -based medicine ( EBM ) ranks different medical research methods on a hierarchy , at the top of which are r and omized controlled trials ( RCTs ) and systematic review s or meta-analyses of RCTs . Any study that does not r and omly assign patients to a treatment or a control group is automatically placed at a lower level on the hierarchy . This article argues that what matters is whether the treatment and control groups are similar with respect to potential confounding factors , not whether they got that way through r and omization . Moreover , nonr and omized studies tend to have other characteristics that make them useful sources of evidence , in that they tend to last longer and to enroll more patients than do r and omized trials . Replacing the sharp dichotomy between r and omized and nonr and omized studies with a continuum from “ clean ” studies ( which have high internal validity but whose results do not readily generalize to clinical practice ) to pragmatic studies ( which are design ed to more closely reflect clinical practice ) would also make a place for outcomes research and research using clinical data bases , which are not included in the current hierarchy of evidence but which can provide important information about the safety and efficacy of treatments Aim . This paper reports a systematic review and critical appraisal of the evidence on the effectiveness of behavioral therapies such as yoga and mindfulness practice s for stroke rehabilitation . Background . The experience of stroke can have a negative impact on both psychological and physical health and on quality of life . Yoga and relevant practice s are promising therapies that have been used with patients with a variety of conditions . In order to draw conclusions on effectiveness for stroke patients , the evidence requires systematic assessment . Methods . A comprehensive search of major biomedical and complementary medicine data bases was conducted . Relevant research was categorized by study type and appraised according to study design . Results . Five r and omized controlled clinical trials and four single case studies were found . Additionally , one qualitative research study was identified . Studies reported positive results , including improvements in cognition , mood , and balance and reductions in stress . Modifications to different yoga practice s make comparison between studies difficult , and a lack of controlled studies precludes any firm conclusions on efficacy . Conclusion . Yoga and mindfulness could be clinical ly valuable self-administered intervention options for stroke rehabilitation . Further research is needed to evaluate these specific practice s and their suitability in stroke rehabilitation Summary Aim To evaluate the educational effectiveness of a clinical ly integrated e-learning course for teaching basic evidence -based medicine ( EBM ) among postgraduate medical trainees compared to a traditional lecture-based course of equivalent content . Methods We conducted a cluster r and omized controlled trial to compare a clinical ly integrated e-learning EBM course ( intervention ) to a lecture-based course ( control ) among postgraduate trainees at foundation or internship level in seven teaching hospitals in the UK West Midl and s region .  Knowledge gain among participants was measured with a vali date d instrument using multiple choice questions . Change in knowledge was compared between groups taking into account the cluster design and adjusted for covariates at baseline using generalized estimating equations ( GEE ) model . Results There were seven clusters involving teaching of 237 trainees ( 122 in the intervention and 115 in the control group ) . The total number of postgraduate trainees who completed the course was 88 in the intervention group and 72 in the control group . After adjusting for baseline knowledge , there was no difference in the amount of improvement in knowledge of EBM between the two groups . The adjusted post course difference between the intervention group and the control group was only 0.1 scoring points ( 95 % CI −1.2–1.4 ) . Conclusion An e-learning course in EBM was as effective in improving knowledge as a st and ard lecture-based course . The benefits of an e-learning approach need to be considered when planning EBM curricula as it allows st and ardization of teaching material s and is a potential cost-effective alternative to st and ard lecture-based teaching Background Our primary objective in this study was to measure family physicians ' knowledge of the key elements that go into assessing the validity and interpreting the results in three different types of studies : i ) a r and omized controlled trial ( RCT ) ; ii ) a study evaluating a diagnostic test ; and iii ) a systematic review ( SR ) . Our secondary objectives were to determine the relationship between the above skills and age , gender , and type of practice . Methods We obtained a r and om sample of 1000 family physicians in Ontario from the College of Family Physicians of Canada data base . These physicians were sent a question naire in the mail with follow-up mailings to non-responders at 3 and 8 weeks . The question naire was design ed to measure knowledge and underst and ing of the basic concepts of critical appraisal skills . Based on the responses to the questions an Evidence Based Medicine ( EBM ) Knowledge Score was determined for each physician . Results A response rate of 30.2 % was achieved . The respondents were younger and more likely to be recent graduates than the population of Ontario Family Physicians as a whole . This was an expected outcome . Just over 50 % of respondents were able to answer questions concerning the critical appraisal of methods and the interpretation of results of research articles satisfactorily . The average score on the 12-point EBM Knowledge Scale was 6.4 . The younger physicians scored higher than the older physicians , and academic physicians scored higher than community-based physicians . Scores of male and female physicians did not differ . Conclusions We have shown that in a population of physicians which is younger than the general population of physicians , about 50 % have reasonable knowledge regarding the critical appraisal of the methods and the interpretation of results of a research article . In general , younger physicians were more knowledgeable than were older physicians . EBM principles were felt to be important to the practice of medicine by 95 % of respondents Twenty years ago , you could read all the literature in your field , said reference librarian Kathy Robbins , PhD , MLIS , scanning shelf after shelf of medical journals at the University of Minnesota Bio-Medical Library in Minneapolis . Now , 6000 journal articles are published each day . Merely keeping up with this torrent of information in one 's own specialty is difficult enough . Synthesizing and applying the knowledge to patient care verges on the impossible without some sort of guidance . Fortunately , this guidance is available . Bringing the fruits of new research to the bedside takes at least four levels of review , said Brian Haynes , MD , PhD , professor and chair of the department of clinical epidemiology at McMaster University in Hamilton , Ontario , Canada . Publications such as ACP Journal Club ( of which Haynes is the editor ) collect relevant trials ; the Cochrane Collaboration synthesizes studies of a given research question ; Evidence -Based Medicine Review s integrates the material ; and Clinical Evidence from the British Medical Journal organizes the information according to clinical topic areas , bringing the material closer to practitioners . The goal of the Cochrane Collaboration is to improve the quality of decisions in health care by preparing , maintaining , and promoting the accessibility of systematic review s of the effects of health care interventions . The Cochrane Collaboration has consistently used r and omized , controlled trials ( RCTs ) as the principal focus of its review s. For medical research , The Cochrane Collaboration is a good place to start , said Robbins . If the answer is there , you save time , because the Collaboration has already done the work of search ing journals . The Cochrane Collaboration and Evidence -Based Medicine The Cochrane Collaboration , which is almost a decade old , has a special flavor because its members receive no financial compensation for their contributions . Another noteworthy aspect of the Collaboration is its origin , which stems from the inspiration of one person . Archibald L. Cochrane was a charismatic British epidemiologist whose call for a hard look at how to tell which interventions did more harm than good inspired the formation of a worldwide consortium that prepares systematic review s of r and omized clinical trials . Both evidence -based medicine and the Cochrane Collaboration have roots in the same soil , said Haynes . The origins were n't spontaneous on either side of the Atlantic , said Haynes . Public investment in health care research after World War II had finally produced results that had gone from the laboratory to r and omized , controlled trials . At that point , there was still a gap between evidence and practice . Closing that gap meant knowing which interventions worked and how well . At McMaster , this led to work by Haynes and David Sackett , joined by Alvan Feinstein at Yale , and others , in what was then called critical appraisal of medical literature . ( According to Haynes , the term evidence -based medicine was not introduced until 1991 in an article by Gordon Guyatt in ACP Journal Club . ) In Britain , similar impulses led to the Cochrane Collaboration . Archie Cochrane : A History Kay Dickersin , PhD , codirector of the Collaboration 's New Engl and Center , has written that Archie Cochrane was one of the first to advance the notion that health services must be evaluated on the basis of scientific evidence rather than on clinical impression , anecdotal experience , expert opinion , or tradition .  Cochrane was born in Scotl and in 1909 , graduated from the University of Cambridge , and studied medicine at University Hospital in London . He joined the Royal Army Medical Corps in 1939 and was taken prisoner in 1941 when the German army overran British forces defending the Greek isl and of Crete .  Cochrane spent the rest of the war in prisoner-of-war camps in Greece and Germany , often as the only medical officer serving thous and s of fellow prisoners . Some of the prisoners in the camp in Greece developed edema in their legs , which Cochrane hypothesized was a form of beriberi caused by vitamin B deficiency . He divided his patients into two groups and added yeast to the diet of one group . The intervention worked , and he then persuaded German army officials at the camp to provide yeast to all inmates . It was , Cochrane wrote , his first , worst , and most successful trial ( Cochrane AL . Br Med J [ Clin Res Ed ] . 1984;289:1726 - 7 ) . Later in Germany , when caring for prisoners with tuberculosis , he lamented the lack of hard evidence on whether and when to perform pneumothorax or thoracoplasty . These experiences and observations inspired a postwar career in epidemiology . After the war , Cochrane returned to London and studied statistics under Bradford Hill ( who would publish the first major r and omized clinical trial , on streptomycin to treat pulmonary tuberculosis , in 1948 ) . Cochrane settled in Cardiff , Wales , where over the next 20 years , he studied the epidemiology of tuberculosis and pneumoconiosis . In 1972 , Cochrane published Effectiveness and Efficiency : R and om Reflections on Health Services , in which he argued that r and omized clinical trials could separate valuable interventions from harmful or useless ones . Seven years later , he wrote : It is surely a great criticism of our profession that we have not organized a critical summary , by specialty or subspecialty , adapted periodically , of all relevant r and omized , controlled trials . Cochrane was especially critical of obstetrics and gynecology , which had failed to evaluate properly new innovations in the field ( such as the move to universal hospital delivery for childbirth and the introduction of Papanicolaou smears for cancer screening of the cervix ) before widespread introduction . Iain Chalmers , an obstetrician in Cardiff who knew Cochrane and his work , found Cochrane 's ideas compelling . If one is going to make rational use of limited re sources for health care , one needs to know which of the many things that people are doing within health care have been shown in reliable research studies to be more likely to do good than harm , said Chalmers recently . And the search for and analysis of the evidence needed to provide this information base should be systematic . The First RCT Registry Thus inspired , Chalmers set out in 1974 to create a comprehensive register of all r and omized clinical trials in perinatal medicine ( pregnancy through postpartum day 28 ) . At the time , a MEDLINE search might have retrieved barely half of all trials published after 1965 . Chalmers directed a team of volunteers in h and search ing 50 journals , going as far back as 1940 . They accumulated 3500 trial reports , and their compilation result ed in the publication in 1985 of A Classified Bibliography of Controlled Trials in Perinatal Medicine , 19401984 . Rapid progress in the field , however , meant that the volume was out of date almost immediately after it was printed , said Dickersin . A regularly up date d , electronic version first appeared in 1988a harbinger of later storage and distribution systems ( Dickersin K , Manheimer E. Clin Obstet Gynecol . 1998;41:315 - 31 ) . Further analytic work by Chalmers and others based on this bibliographic material yielded several volumes on perinatal medicine , including a 350-page paperback , Guide to Effective Care in Pregnancy and Childbirth , that presented the conclusions of the full versions in ways immediately useful to women using the maternity services . The systematic review s that were initially published on paper in three books were then kept up to date in a semi-annual electronic publication called The Oxford Data base of Perinatal Trials . Birth of the Cochrane Collaboration In 1993 , Chalmers and an international group of about 70 others jointly announced the formation of the Cochrane Collaboration to prepare , maintain , and disseminate systematic review s of the effects of health care interventions . Dickersin was the principal U.S. representative at the inaugural meeting . The Collaboration 's systematic review s entail exhaustive literature search es and the selection and analysis of studies based on explicit , prespecified criteria , sometimes , but not always , using meta-analyses , which are formal , mathematical combinations of numerical results . With the traditional review article , there are no guidelines about how to do it and no transparency for the reader . You ca n't tell if they 've really plowed through the literature or just picked over their file cabinets , said Dickersin , now associate professor of community health at Brown University School of Medicine in Providence , Rhode Isl and . Meta-analyses , to be good , must be of high quality and appropriate . Sometimes they may lump data together from both r and omized and observational trials or exhibit other biases . When poor meta-analyses are associated with systematic review s , people may assume guilt by association . Clinical practice guidelines may be an outgrowth of systematic review s , but they should be done by different peopleclinicians and professional organizations , she said . How Cochrane Works The Collaboration is made up of review groups , centers , fields , methods groups , and the consumer network . The review groups search for , collect , and analyze RCTs relating to specific health conditions . The 15 centers that constitute the Collaboration are geographically dispersed across 13 countries . In addition to coordinating the review activities within their region , each center also performs specialized functions . The San Francisco Center , for instance , advises on the electronic feedback and peer- review system . An elected 12-member steering group oversees the entire organization , supported by a small secretariat based in Oxford . The real work of the Collaboration takes place in the review groups , building on the model established by Chalmers ' work on perinatal medicine . Initiative for review s generally comes from members who suggest topics to the groups , explained Lisa A. Bero , PhD , associate professor of health policy studies
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 .