Teaching evidence-based medicine skills can change practice in a community hospital Principles of evidence based medicine Methodology and reporting of randomised controlled trials. Evidence-based medicine in the ICU: important advances and limitations. Evidence-based medicine: what it is and what it is not. Evidence-based medicine training during residency: a randomized controlled trial of efficacy The evidence house: how to build an inclusive base for complementary medicine. Some Observations on “Observational” Research Evaluating the teaching of evidence-based medicine. A Controlled Comparison Study of the Efficacy of Training Medical Students in Evidence-Based Medicine Literature Searching Skills Teaching of evidence-based medicine to medical students in Mexico: a randomized controlled trial The Impact of an Evidence-Based Medicine Educational Intervention on Primary Care Physicians: A Qualitative Study The Clinical Inadequacy of Evidence-Based Medicine and the Need for a Conceptual Framework Based on Clinical Judgment Impact of an Evidence-Based Medicine Curriculum on Resident Use of Electronic Resources: A Randomized Controlled Study 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. Effectiveness of evidence-based medicine on knowledge, attitudes, and practices of family planning providers: a randomized experiment in Jordan Evidence-based medicine targets the individual patient. Part 1: how clinicians can use study results to determine optimal individual care.
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 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 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 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 The evidence -based medicine ( EBM ) related concepts of hierarchy of evidence , meta-analyses , confidence intervals , study design , etc . are nowadays so widespread , that clinicians willing to use today 's medical literature with underst and ing have no choice but to become familiar with EBM principles and method ologies . Although surgeons may perceive that evidence -based medicine m and ates a strict adherence to r and omised trials , it more accurately involves informed and effective use of all types of evidence ( from meta- analysis of r and omised trials to individual case series and case reports . With the ever-increasing amount of available information , surgeons must consider a shift in paradigm from traditional practice to one that involves question formulation , validity assessment of available studies and appropriate application of research evidence to individual patients Background Evidence -based medicine ( EBM ) has been widely integrated into residency curricula , although results of r and omized controlled trials and long term outcomes of EBM educational interventions are lacking . We sought to determine if an EBM workshop improved internal medicine residents ' EBM knowledge and skills and use of secondary evidence re sources . Methods This r and omized controlled trial included 48 internal medicine residents at an academic medical center . Twenty-three residents were r and omized to attend a 4-hour interactive workshop in their PGY-2 year . All residents completed a 25-item EBM knowledge and skills test and a self-reported survey of literature search ing and re source usage in their PGY-1 , PGY-2 , and PGY-3 years . Results There was no difference in mean EBM test scores between the workshop and control groups at PGY-2 or PGY-3 . However , mean EBM test scores significantly increased over time for both groups in PGY-2 and PGY-3 . Literature search es , and re source usage also increased significantly in both groups after the PGY-1 year . Conclusions We were unable to detect a difference in EBM knowledge between residents who did and did not participate in our workshop . Significant improvement over time in EBM scores , however , suggests EBM skills were learned during residency . Future rigorous studies should determine the best methods for improving residents ' EBM skills as well as their ability to apply evidence during clinical practice 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 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 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 Purpose Many educational programs seek to develop skills in evidence -based medicine ( EBM ) . The authors examined the efficacy of teaching the EBM skill of efficiently search ing the research literature . They compared students who received brief training in EBM search ing skills with those who did not , and assessed the quality of literature search ing one month after that training . Method The authors used a nonr and omized control group study design to quantify the impact of a single , brief ( two-hour ) instructional intervention on EBM-based techniques for search ing Medline for evidence related to a clinical problem provided to the students . Ninety-two fourth-year medical students ( 34 intervention , 58 control ) at the University of Michigan participated in a four-week EBM elective between 2001 and 2003 . The authors conducted a preintervention assessment of search ing skills , followed by a repeat assessment one month after the intervention . Search quality was judged by medical librarians using a structured clinical scenario and scoring algorithm . Results Data for 30 intervention and 40 control students could be analyzed . Intervention students had fewer search errors and correspondingly higher quality search es than did control students . The educational intervention accounted for approximately 8 % of the variance in both of these outcomes . The most common search errors were a lack of Medical Subject Headings ( MeSH ) explosion , missing MeSH terms , lack of appropriate limits , failure to search for best evidence , and inappropriate combination of all search concepts . Conclusions This study provides evidence that a single , brief training session can have a marked beneficial effect on the quality of subsequent , short-term EBM literature search ing performance outcomes Background Evidence -Based Medicine ( EBM ) is an important competency for the healthcare professional . Experimental evidence of EBM educational interventions from rigorous research studies is limited . The main objective of this study was to assess EBM learning ( knowledge , attitudes and self-reported skills ) in undergraduate medical students with a r and omized controlled trial . Methods The educational intervention was a  one-semester EBM course in the 5th year of a public medical school in Mexico . The study design was an experimental parallel group r and omized controlled trial for the main outcome measures in the 5th year class ( M5 EBM vs. M5 non-EBM groups ) , and quasi-experimental with static-groups comparisons for the 4th year ( M4 , not yet exposed ) and 6th year ( M6 , exposed 6 months to a year earlier ) groups . EBM attitudes , knowledge and self-reported skills were measured using Taylor ’s question naire and a summative exam which comprised of a 100-item multiple-choice question ( MCQ ) test . Results 289 Medical students were assessed : M5 EBM=48 , M5 non-EBM=47 , M4=87 , and M6=107 . There was a higher reported use of the Cochrane Library and secondary journals in the intervention group ( M5 vs. M5 non-EBM ) . Critical appraisal skills and attitude scores were higher in the intervention group ( M5 ) and in the group of students exposed to EBM instruction during the previous year ( M6 ) . The knowledge level was higher after the intervention in the M5 EBM group compared to the M5 non-EBM group ( p<0.001 , Cohen 's d=0.88 with Taylor 's instrument and 3.54 with the 100-item MCQ test ) . M6 Students that received the intervention in the previous year had a knowledge score higher than the M4 and M5 non-EBM groups , but lower than the M5 EBM group . Conclusions Formal medical student training in EBM produced higher scores in attitudes , knowledge and self-reported critical appraisal skills compared with a r and omized control group . Data from the concurrent groups add validity evidence to the study , but rigorous follow-up needs to be done to document retention of EBM abilities Background Attitudes and barriers to implementing EBM have been examined extensively , but scant evidence exists regarding the impact of EBM teaching on primary care physicians ’ point of care behavior . Objective Gaining insight into behavioral and attitudinal changes of facilitators and participants during a multifaceted EBM educational intervention . Design , setting , and participants A qualitative study on primary care physicians and facilitators from a large HMO selected from the intervention arm of a parallel controlled trial using purpose ful sampling . We conducted focus groups with 13 facilitators and 17 physicians and semi-structured interviews with 10 facilitators and 11 physicians . Results Both facilitators and participants believed EBM enhanced the quality of their practice . The intervention affected attitudes and knowledge , but had little impact on physicians ’ ability to utilize pre-appraised re sources at the point of care . Using EBM re sources during consultation was perceived to be a complex task and impractical in a busy setting . Conversely , a positive impact on using medication data bases was noted . Medication data bases were perceived as easy to use during consultations in which the benefits outweighed the barriers . The intervention prompted physicians to write down clinical questions more frequently and to search for answers at home . Conclusions This study underlines the need not only to enhance EBM skills , but also to improve the ease of use of EBM re sources at the point of care . Tasks should be simplified by tailoring evidence -based information retrieval systems to the busy clinical schedule . Participants ’ recommendations to establish an HMO decision support service should be considered Each therapeutic act may be seen as a result of multiple ingredients that may be specific or nonspecific [ 6 ] . Expectations , preferences , motivation , and patient-doctor interactions are examples of variables that may affect treatment outcome [ 6 , 7 ] . The changed spectrum of medical disorders ( shifted toward aging and chronicity ) and the interindividual differences in health priorities make the focus on single diseases potentially misleading , whereas there is growing awareness that the aim of the treatment should refer to personal goals ( from attainment of cure to prevention of recurrence , from removal of functional impairment to alleviation of symptoms ) [ 8 ] . EBM does not do justice to the importance of these interactions and provides an oversimplified and reductionistic view of treatment . Finally , the presence of investigators with substantial financial conflicts of interest in panels concerned with clinical guidelines and the excessive reliance of metaanalyses on industry-funded studies constitute two major sources of bias in literature interpretation [ 1 , 9 ] . Horwitz et al. [ 10 ] developed a method of clinical inquiry within RCT that can enhance the applicability of results to clinical decision making . Reanalyzing the BetaBlocker Heart Attack Trial , they found that propranolol reduced the risk of dying for the ‘ average ’ patient who survived an acute myocardial infa rct ion , whereas it was harmful in a subgroup characterized by specific cotherapy histories . If we accept the possibility that a treatment The gap between clinical guidelines developed by evidence -based medicine ( EBM ) and the real world of clinicians and patients has been widely recognized . There is currently little evidence that EBM has actually improved patient care [ 1 ] . It is thus not surprising that most of the time clinicians rely more on their own experience and that of their colleagues ( tacit knowledge or ‘ mindlines ’ ) than on explicit evidence from research [ 2 ] . Feinstein and Horwitz [ 3 ] were among the first to warn about excessive reliance on r and omized controlled trials ( RCT ) and meta-analyses that were not intended to answer questions about the treatment of individual patients . The results of these types of trials may show comparative efficacy of treatments for the average r and omized patient but not for those whose characteristics , such as severity of symptoms , comorbidity and other clinical features , depart from st and ard presentations [ 3 ] . In addition , meta-analyses often include highly heterogeneous studies and ascribe conflicting results to r and om variability , whereas different outcomes may reflect different patient population s , enrollment and protocol characteristics [ 4 ] . Even though personalized medicine , described as genomicsbased knowledge , has promised to approach each patient as the biological individual he/she is , the practical applications still have a long way to go and neglect of social and behavioral features may actually lead to ‘ depersonalized ’ medicine [ 5 ] . Other limitations have emerged over time . Received : July 11 , 2014 Accepted after revision : July 21 , 2014 Published online : December 24 , Background Evidence -based medicine ( EBM ) is widely taught in residency , but evidence for effectiveness of EBM teaching on changing residents ’ behavior is limited . Objective To investigate the impact of an EBM curriculum on residents ’ use of evidence -based re sources in a simulated clinical experience . Design / Participants Fifty medicine residents r and omized to an EBM teaching or control group .  Measurements A vali date d test of EBM knowledge ( Fresno test ) was administered before and after intervention . Post intervention , residents twice completed a  Web-based , multiple-choice instrument  ( 15 items ) comprised of clinical vignettes , first without then with access to electronic re sources . Use of electronic re sources was tracked using ProxyPlus software . Within group pre – post differences and between group post-test differences were examined . Results There was more improvement in EBM knowledge ( 100-point scale ) for the intervention group compared to the control group ( mean score increase 22 vs. 12 , p = 0.012 ) . In the simulated clinical experience , the most commonly accessed re sources were Ovid ( 71 % of residents accessed ) and InfoPOEMs ( 62 % ) for the EBM group and Upto Date ( 67 % ) and MDConsult ( 58 % ) for the control group . Residents in the EBM group were more likely to use evidence -based re sources than the control group . Performance on clinical vignettes was similar between the groups both at baseline ( p = 0.19 ) and with access to information re sources ( p = 0.89 ) . Conclusions EBM teaching improved EBM knowledge and increased use of evidence -based re sources by residents , but did not improve performance on Web-based clinical vignettes . Future studies will need to examine impact of EBM teaching on clinical outcomes 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 Background Provider misconceptions and biases about contraceptive methods are major barriers to family planning access for women in low- and middle-income countries , including Jordan .  Evidence -Based Medicine ( EBM ) programs aim to reduce biases and misconceptions by providing doctors with the most up-to- date scientific evidence on contraceptive methods . Methods We evaluate the effects of an EBM program  conducted in Jordan on private providers ’ knowledge , attitudes , and practice s. Family planning providers r and omly assigned to a treatment group were invited to attend a roundtable seminar on the injectable contraceptive Depot Medroxy Progesterone Acetate ( DMPA ) , and to receive two 15 min one-on-one educational visits that reinforce the messages from the seminar . Results There was low compliance with the EBM program . The study fails to detect an impact on providers ’ knowledge of DMPA ’s side effects or on reported clinical practice s. There is suggestive evidence of a positive impact on providers ’ attitudes toward and confidence in prescribing the contraceptive to their patients . There is also evidence of positive selection into program participation . Conclusions We conclude that EBM may not be effective as a st and -alone program targeting a family planning method with a high level of provider and consumer bias . Evidence of positive selection into program participation underscores the importance of r and omization to avoid overestimating the true effects of interventions .Trial registration AEA RCT Registry , AEA RCT R0000539 , Despite increasing acknowledgment of its importance ( 1 ) , some clinicians continue to characterize evidence -based medicine ( EBM ) as focusing on groups of patients and neglecting the individual ( 2 , 3 ) . In this 2-part editorial , we will describe EBM tools that address individual patient decision-making . In this first part we will focus on guides for applying research evidence and for determining the benefit-to-risk ratio in individual patients . 1 . EBM provides guides for addressing the applicability of r and omized controlled trials to individual patients EBM assists clinicians who ponder how generalizable r and omized controlled trial ( RCT ) results are to their individual patients and their circumstances ( Table ) ( 4 - 6 ) . That guidance directs clinicians to look for possible differences in biological factors , socioeconomic characteristics , and attitudinal or behavioral characteristics of individual patients that might modulate treatment effects ( 7 ) . For instance , antibiotics for otitis media seem to be most beneficial in children < 2 years of age with bilateral acute otitis media and in children with both acute otitis media and otorrhea ( 8) . Health care characteristics should also be considered because research studies are often conducted at specialized centers with capabilities and expertise exceeding those available for routine patient care . This factor is of particular concern when applying the results of trials conducted in high-income setting s to low-income setting s or to trials in which the clinician 's skill is a central aspect of the intervention , such as surgical trials where the average surgeon might not be as skilled or experienced with the procedure as surgeons in the study ( 9 ) . Finally , outcome characteristics should be considered . RCTs focused on surrogate endpoints ( e.g. , bone density rather than fractures ) are less directly applicable to patients than trials focused on patient-important outcomes . Although clinicians should consider these criteria when applying the results of research studies to individual patients , EBM emphasizes that treatment effects are usually sufficiently similar across patients with the same condition to allow application to the individual after patient-specific baseline risk is considered . Table 1 . Criteria to consider when applying the results of research studies to individual patients Patient characteristics Health care characteristics Outcome characteristics Biologic factors ( sex , comorbid conditions , race , age , severity of pathology)Patient compliance with treatment requirements Compliance of health care providers with treatment requirementsRe sources available for implementation ( e.g. , availability of monitoring)Expertise of clinicians Did the study measure an outcome of importance to the individual patient ? 2 . Consideration of individual baseline risk to establish individual benefits and risks In considering the risks and benefits of an intervention to an individual , patients and clinicians will probably find absolute measures ( e.g. , risk difference ) more intuitive and interpretable than relative measures ( e.g. , relative risk ) . The number of patients who would need to be treated to prevent 1 additional adverse event or to create 1 additional beneficial outcome number needed to treat (NNT)is a useful way to characterize the absolute magnitude of a treatment effect ( 10 ) . Although relative measures of effectiveness are similar across patient groups , absolute measures vary depending on the underlying baseline risk . Thus , average risks ( e.g. , difference between control and treatment event rates in an RCT and the corresponding NNT ) are of limited use in individualizing care . What patients want to know is their personal absolute risk reduction , and what clinicians need is the NNT for a group of individuals resembling their patient . EBM offers approaches to establish individual benefits and risks via individual patient expected event rates ( 11 ) . Clinicians can acquire information about baseline risks that are more relevant to individual patients from subgroups of patients in studies on prognosis , epidemiologic studies of incidence of disease , clinical prediction guides ( 12 ) , or RCTs . * Clinicians can use this information to calculate the expected event rate in patients who receive the intervention by multiplying the baseline event rate by the relative risk . Consider this example . A 40-year-old man presenting with an uncomplicated nonST elevation myocardial infa rct ion can expect an absolute risk reduction for dying in the next month of approximately 0.4 % if he received clopidogrel ( baseline risk of 2 % , relative risk reduction 20 % , 2 % 0.2 = 0.4 % ) . This translates into an NNT of 250 ( 100/0.4 ) . The figures for a 70-year-old man presenting with an infa rct ion complicated by heart failure show much greater absolute benefit ( baseline risk 40 % , relative risk reduction 20 % , absolute risk reduction 8 % , NNT 12 to 13 ) . When study data are unavailable , clinicians can use their personal experience and the experience of their colleagues to estimate an individual patient 's baseline risk . Conclusion EBM complements the traditional approach to individualized decision-making ( the clinicians ' instincts ) with a set of rigorous tools and strategies . These include guides to help decide on the applicability of RCTs to the individual and tools to quantify the benefits and risks for the individual in making particular treatment decisions . The process of individualizing care incorporates additional strategies that we will describe in the second part of this editorial
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 .