Evidence-Based Medicine A New Approach to Teaching the Practice of Medicine Evidence-Based Medicine Working Group

A NEW paradigm for medical practice dose of phenytoin intravenously and the year is between 43% and 51%, and at 3 is emerging. Evidence-based medicine drug is continued orally. A computed years the risk is between 51% and 60%. de-emphasizes intuition, unsystematic tomographic head scan is completely nor¬ After a seizure-free period of 18 months clinical experience, and pathophysiolog- mal, and an electroencephalogram shows his risk of recurrence would likely be ic rationale as sufficient grounds for clin- only nonspecific findings. The patient is less than 20%. She conveys this infor¬ ical decision making and stresses the very concerned about his risk of seizure mation to the patient, along with a rec¬ examination of evidence from clinical re- recurrence. How might the resident ommendation that he take his medica¬ search. Evidence-based medicine re- proceed? tion, see his family doctor regularly, and quires new skills of the physician, in- have a review of his need for medication cluding efficient literature searching and The Way of the Past ifhe remains seizure-free for 18 months. the application of formal rules of evi- Faced with this situation as a clinical The patient leaves with a clear idea of dence evaluating the clinical literature. clerk, the resident was told by her se¬ his likely prognosis. An important goal of our medical res- nior resident (who was supported in his idency program is to educate physicians view by the attending physician) that A PARADIGM SHIFT in the practice of evidence-based med- the risk of seizure recurrence is high Thomas Kuhn has described scientific icine. Strategies include a weekly, for- (though he could not put an exact num¬ paradigms as ways of looking at the mal academic half-day for residents, de- ber on it) and that was the information world that define both the problems that voted to learning the necessary skills; that should be conveyed to the patient. can legitimately be addressed and the recruitment into teaching roles of phy- She now follows this path, emphasizing range of admissible evidence that may sicians who practice evidence-based to the patient not to drive, to continue bear on their solution.4 When defects in medicine; sharing among faculty of ap- his medication, and to see his family an existing paradigm accumulate to the proaches to teaching evidence-based physician in follow-up. The patient leaves extent that the paradigm is no longer medicine; and providing faculty with in a state of vague trepidation about his tenable, the paradigm is challenged and feedback on their performance as role risk of subsequent seizure. replaced by a new way of looking at the models and teachers of evidence-based world. Medical practice is changing, and medicine. The influence of evidence- The Way of the Future the change, which involves using the based medicine on clinical practice and The resident asks herselfwhether she medical literature more effectively in medical education is increasing. knows the prognosis of a first seizure guiding medical practice, is profound and realizes she does not. She that it can be called CLINICAL SCENARIO proceeds enough appropriately to the library and, using the Grateful a paradigm shift. A junior medical resident working in Med program,1 conducts a computerized The foundations of the paradigm shift a teaching hospital admits a 43-year-old literature search. She enters the Med¬ lie in developments in clinical research previously well man who experienced a ical Subject Headings terms epilepsy, over the last 30 years. In 1960, the ran¬ witnessed grand mal seizure. He had prognosis, and recurrence, and the pro¬ domized clinical trial was an oddity. It is never had a seizure before and had not gram retrieves 25 relevant articles. Sur¬ now accepted that virtually no drug can had any recent head trauma. He drank veying the titles, one2 appears directly enter clinical practice without a demon¬ alcohol once or twice a week and had not relevant. She reviews the paper, finds stration of its efficacy in clinical trials. had alcohol on the day of the seizure. that it meets criteria she has previously Moreover, the same randomized trial Findings on physical examination are learned for a valid investigation ofprog¬ method increasingly is being applied to normal. The patient is given a loading nosis,3 and determines that the results surgical therapies6 and diagnostic tests.6 are applicable to her patient. The search Meta-analysis is gaining increasing ac¬ costs the resident $2.68, and the entire ceptance as a method of summarizing the A complete list of members of the Evidenced-Based process (including the trip to the library results of a number of randomized trials, Medicine Working Group appears at the end of this ar- and the time to make a photocopy of the and ultimately may have as profound an ticle. article) took half an hour. effect on treatment as have Reprint requests to McMaster University Health Sci- setting policy ences Centre, Room 3W10,1200 Main St W, Hamilton, The results ofthe relevant study show randomized trials themselves.7 While Ontario, Canada L8N 3Z5 (Gordon Guyatt, MD). that the patient risk of recurrence at 1 less dramatic, crucial methodological ad-

Downloaded from www.jama.com at Vrije Universiteit on August 22, 2009 vanees have also been made in other ar¬ sense is sufficient to allow one to eval¬ uncertainty and to acknowledge that eas, such as the assessment of diagnostic uate new tests and treatments. management decisions are often made tests8·9 and prognosis.2 4. Content expertise and clinical ex¬ in the face of relative ignorance of their A new philosophy of medical practice perience are a sufficient base from which true impact. and teaching has followed these meth¬ to generate valid guidelines for clinical The new paradigm puts a much lower odological advances. This paradigm shift practice. value on authority.20 The underlying be¬ is manifested in a number of ways. A According to this paradigm clinicians lief is that physicians can gain the skills profusion of articles has been published have a number of options for sorting out to make independent assessments of ev¬ instructing clinicians on how to access,10 clinical problems they face. They can idence and thus evaluate the credibility evaluate,11 and interpret12 the medical reflect on their own clinical experience, of opinions being offered by experts. literature. Proposals to apply the prin¬ reflect on the underlying biology, go to The decreased emphasis on authority ciples of clinical epidemiology to day- a textbook, or ask a local expert. Read¬ does not imply a rejection of what one to-day clinical practice have been put ing the introduction and discussion sec¬ can learn from colleagues and teachers, forward.3 A number of major medical tions of a paper could be considered an whose years of experience have provid¬ journals have adopted a more informa¬ appropriate way of gaining the relevant ed them with insight into methods of tive structured abstract format, which information from a current journal. history taking, physical examination, and incorporates issues of methods and de¬ This paradigm puts a high value on diagnostic strategies. This knowledge sign into the portion of an article the traditional scientific authority and ad¬ can never be gained from formal scien¬ reader sees first.13 The American Col¬ herence to standard approaches, and an¬ tific investigation. A final assumption of lege of Physicians has launched a jour¬ swers are frequently sought from direct the new paradigm is that physicians nal, ACP Journal Club, that summa¬ contact with local experts or reference whose practice is based on an under¬ rizes new publications of high relevance to the writings ofinternational experts.19 standing ofthe underlying evidence will and methodological rigor.14 Textbooks care. The New provide superior patient that provide a rigorous review of avail¬ Paradigm REQUIREMENTS FOR THE able evidence, including a methods sec¬ The assumptions ofthe new paradigm PRACTICE OF EVIDENCE-BASED tion describing both the methodological are as follows: criteria used to systematically evaluate 1. Clinical experience and the devel¬ MEDICINE the validity of the clinical evidence and opment of clinical instincts (particularly The role modeling, practice, and teach¬ the quantitative techniques used for with respect to diagnosis) are a crucial ing of evidence-based medicine requires summarizing the evidence, have begun and necessary part of becoming a com¬ skills that are not traditionally part of to appear.1516 Practice guidelines based petent physician. Many aspects of clin¬ medical training. These include precise¬ on rigorous methodological review ofthe ical practice cannot, or will not, ever be ly defining a patient problem, and what available evidence are increasingly com¬ adequately tested. Clinical experience information is required to resolve the mon.17 A final manifestation is the grow¬ and its lessons are particularly impor¬ problem; conducting an efficient search ing demand for courses and seminars tant in these situations. At the same of the literature; selecting the best of that instruct physicians on how to make time, systematic attempts to record ob¬ the relevant studies and applying rules more effective use of the medical liter¬ servations in a reproducible and unbi¬ of evidence to determine their validity3; ature in their day-to-day patient care.3 ased fashion markedly increase the con¬ being able to present to colleagues in a We call the new paradigm "evidence- fidence one can have in knowledge about succinct fashion the content of the ar¬ based medicine."18 In this article, we de¬ patient prognosis, the value of diagnos¬ ticle and its strengths and weaknesses; scribe how this approach differs from tic tests, and the efficacy of treatment. and extracting the clinical message and prior practice and briefly outline how In the absence of systematic observa¬ applying it to the patient problem. We we are building a residency program in tion one must be cautious in the inter¬ will refer to this process as the critical which a key goal is to practice, act as a pretation of information derived from appraisal exercise. role model, teach, and help residents clinical experience and intuition, for it Evidence-based medicine also involves become highly adept in evidence-based may at times be misleading. applying traditional skills of medical medicine. We also describe some of the 2. The study and understanding of training. A sound understanding of problems educators and medical prac¬ basic mechanisms of disease are neces¬ pathophysiology is necessary to inter¬ titioners face in implementing the new sary but insufficient guides for clinical pret and apply the results of clinical re¬ paradigm. practice. The rationales for diagnosis and search. For instance, most patients to treatment, which follow from basic whom we would like to the The Former generalize Paradigm pathophysiologic principles, may in fact results of randomized trials would, for The former paradigm was based on be incorrect, leading to inaccurate pre¬ one reason or another, not have been the following assumptions about the dictions about the performance of diag¬ enrolled in the most relevant study. The knowledge required to guide clinical nostic tests and the efficacy of treat¬ patient may be too old, be too sick, have practice. ments. other underlying illnesses, or be unco¬ 1. Unsystematic observations from 3. Understanding certain rules of operative. Understanding the underly¬ clinical experience are a valid way of evidence is necessary to correctly in¬ ing pathophysiology allows the clinician building and maintaining one's knowl¬ terpret literature on causation, progno¬ to better judge whether the results are edge about patient prognosis, the value sis, diagnostic tests, and treatment applicable to the patient at hand and of diagnostic tests, and the efficacy of strategy. also has a crucial role as a conceptual treatment. It follows that clinicians should reg¬ and memory aid. 2. The study and understanding of ularly consult the original literature (and Another traditional skill required of basic mechanisms of disease and patho- be able to critically appraise the meth¬ the evidence-based physician is a sen¬ physiologic principles are a sufficient ods and results sections) in solving clin¬ sitivity to patients' emotional needs. Un¬ guide for clinical practice. ical problems and providing optimal pa¬ derstanding patients' suffering21 and how 3. A combination of thorough tradi¬ tient care. It also follows that clinicians that suffering can be ameliorated by the tional medical training and common must be ready to accept and live with caring and compassionate physician are

Downloaded from www.jama.com at Vrije Universiteit on August 22, 2009 Evaluation Form for Clinical Teaching Unit Attending Physicians Rating Domain Unsatisfactory Needs Improvement Satisfactory Good Excellent Role model of practice Seldom cites evidence Often fails to substantiate Usually substantiates Substantiates decisions; Always substantiates of evidence-based to support clinical decisions with evidence decisions with is aware of decisions or medicine decisions evidence methodological issues acknowledges limitations of evidence Leads practice of Never assigns problems Produces suboptimal volume Assigns problems and Discusses literature Same as "Good" rating, evidence-based to be resolved or follow-through of problem follows through with retrieval, methodology and makes it exciting medicine through literature resolution through literature discussion, including of papers, application and fun methodology to individual patient fundamental requirements for medical articles and arriving at bottom lines re¬ ical teaching roles available to them. practice. These skills can be acquired garding the strength of evidence and Second, a program of more rigorous through careful observation of patients how it bears on the clinical problem. evaluation of attending physicians has and of physician role models. Here too, They learn to present the methods and been instituted. One of the areas eval¬ though, the need for systematic study results in a succinct fashion, emphasiz¬ uated is the extent to which attending and the limitations of the present evi¬ ing only the key points. A wide-ranging physicians are effective in teaching ev¬ dence must be considered. The new par¬ discussion, including issues of underly¬ idence-based medicine. The relevant adigm would call for using the techniques ing pathophysiology and related ques¬ items from the evaluation form are re¬ of behavioral science to determine what tions of diagnosis and management, fol¬ produced in the Table. patients are really looking for from their lows presentation of the articles. Third, because it is new to both teach¬ physicians22 and how physician and pa¬ The second part of the half-day is de¬ ers and learners, and because most clin¬ tient behavior affects the outcome of voted to the physical examination. Clin¬ ical teachers have observed few role care.23 Ultimately, randomized trials ical teachers present optimal techniques models and have not received formal using different strategies for interact¬ of examination with attention to what is training, teaching evidence-based med¬ ing with patients (such as the random¬ known about their reproducibility and icine is not easy. To help attending phy¬ ized trial conducted by Greenfield and accuracy. sicians improve their skills in this area, colleagues24 that demonstrated the pos¬ 2. Facilities for computerized litera¬ we have encouraged them to form part¬ itive effects of increasing patients' in¬ ture searching are available on the teach¬ nerships, which involve attending the volvement with their care) may be ing medical ward in each of the four partner's clinical rounds, making obser¬ appropriate. teaching hospitals. Costs of searching vations, and providing formal feedback. Since evidence-based medicine in¬ are absorbed by the residency program. One learns through observation and volves skills ofproblem defining, search¬ Residents not familiar with computer through criticisms of one's performance. ing, evaluating, and applying original searching, or the Grateful Med program A number of faculty members have par¬ medical literature, it is incumbent on we use, are instructed at the beginning ticipated in this program. residency programs to teach these skills. of the rotation. Research in our insti¬ To further facilitate attending physi¬ Understanding the barriers to educat¬ tution has shown that MEDLINE cians' improving their skills, the De¬ ing physicians-in-training in evidence- searching from clinical settings is fea¬ partment of Medicine held a retreat de¬ based medicine can lead to more effec¬ sible with brief training.26 A subsequent voted to sharing strategies for effective tive teaching strategies. investigation demonstrated that inter¬ clinical teaching. Part of the workshop, nal medicine house staff who have com¬ attended more than 30 faculty mem¬ EVIDENCE-BASED MEDICINE IN A by puter access on the ward and feedback was devoted to evidence- MEDICAL RESIDENCY bers, teaching concerning their searching do an aver¬ based medicine. Some of the strategies The Internal Medicine Residency Pro¬ age of more than 3.6 searches per that were adduced are briefly summa¬ gram at McMaster University has an month.26 House staff believe that more rized in the next section. explicit commitment to producing prac¬ than 90% oftheir searches that are stim¬ titioners of evidence-based medicine. ulated by a patient problem lead to some EFFECTIVE TEACHING OF While other clinical departments at improvement in patient care.25 EVIDENCE-BASED MEDICINE McMaster have devoted themselves to 3. Assessment of searching and crit¬ teaching evidence-based medicine, the ical appraisal skills is being incorporat¬ Role Modeling commitment is strongest in the Depart¬ ed into the evaluation of residents. Attending physicians must be enthu¬ ment of Medicine. We will therefore fo¬ 4. We believe that the new paradigm siastic, effective role models for the prac¬ cus on the Internal Medicine Residency will remain an academic mirage with tice of evidence-based medicine (even in in our discussion and briefly outline some little relation to the world of day-to-day high-pressure clinical settings, such as of the strategies we are using in imple¬ clinical practice unless physicians-in- intensive care units). Providing a model menting the paradigm shift. training are exposed to role models who goes a long way toward inculcating at¬ 1. The residents spend each Wednes¬ practice evidence-based medicine. As a titudes that lead learners to develop day afternoon at an academic half-day. result, the residency program has skills in critical appraisal. Acting as a At the beginning of each new academic placed major emphasis on ensuring this role model involves specifying the year, the rules of evidence that relate to exposure. strength of evidence that supports clin¬ articles concerning therapy, diagnosis, First, a focus of recruitment for our ical decisions. In one case, the teacher prognosis, and overviews are reviewed. Department of Medicine faculty has can point to a number of large random¬ In subsequent sessions, the discussion been internists with training in clinical ized trials, rigorously reviewed and in¬ is built around a clinical case, and two epidemiology. These individuals have the cluded in a meta-analysis, which allows original articles that bear on the prob¬ skills and commitment to practice evi¬ one to say how many patients one must lem are presented. The residents are dence-based medicine. The residency treat to prevent a death. In other cases, responsible for critically appraising the program works to ensure they have clin- the best evidence may come from ac-

Downloaded from www.jama.com at Vrije Universiteit on August 22, 2009 cepted practice or one's clinical experi¬ Diagnosis.—Has the diagnostic test Institutional experience can also pro¬ ence and instincts. The clinical teacher been evaluated in a patient sample that vide important insights. Diagnostic tests should make it clear to learners on what included an appropriate spectrum ofmild may differ in their accuracy depending basis decisions are being made. This can and severe, treated and untreated dis¬ on the skill of the practitioner. A local be done efficiently. For instance: ease, plus individuals with different but expert in, for instance, diagnostic ultra¬ confused disorders?28 sound Prospective studies suggest that Mr Jones' commonly Was may produce far better results there an blind than the risk of a major vascular event in the first independent, comparison average from the published lit¬ year after his infarct is 4%; a meta-analysis with a "gold standard" of diagnosis?28 erature. The effectiveness and compli¬ of randomized trials of aspirin in this situa¬ Treatment.—Was the assignment of cations associated with therapeutic in¬ tion suggests a risk reduction of 25%; we patients to treatments randomized?29 terventions, particularly surgical pro¬ such would have to treat 100 patients to pre¬ Were all patients who entered the study cedures, may also differ among institu¬ vent an event21; given the minimal expense accounted for at its conclusion?29 tions. When optimal care is taken to and toxicity of low-dose, enteric-coated as¬ Review Articles.—Were both record observations pirin, treating Mr Jones is clearly warranted. explicit reproducibly methods used to determine which arti¬ and avoid bias, clinical and institutional Or: cles to include in the review?30 experience evolves into the systematic How longto treat a patient with antibiotics fol¬ As learners become more sophisticat¬ search for knowledge that forms the core lowing pneumonia has not been systematically ed, additional criteria can be introduced. of evidence-based medicine.32 studied; so, my recommendation that we give The criteria should not be presented in Misinterpretation 2.—Understand¬ Mrs Smith 3 days of intravenous antibiotics such a way that fosters nihilism (if the ing ofbasic investigation and pathophys- and treat her for a total of 10 is days arbitrary; is not it is useless no in evidence-based somewhat shorter or courses of treat¬ study randomized, iology plays part longer and no valuable medicine. ment would be equally reasonable. provides information), but as a way of arrive at the Correction.—The dearth of In the latter of helping adequate type situation, dog¬ strength of inference associated with a evidence demands that clinical problem matic or insistence on a rigid following clinical decision. Teachers can point out solving must rely on an understanding course of action would not be particular instances in which criteria can be vio¬ of underlying pathophysiology. More¬ appropriate. lated without reducing the strength of over, a good understanding of patho¬ inference. is for Critical physiology necessary interpreting Appraisal clinical observations and for appropri¬ It is crucial that critical is¬ appraisal METHODS FOR SCALING THE ate interpretation of evidence (especial¬ sues arise from patient problems that ly in deciding on its generalizability). the learner is BARRIERS TO THE DISSEMINATION currently confronting, OF EVIDENCE-BASED MEDICINE Misinterpretation 3.—Evidence- demonstrating that critical appraisal is based medicine standard About ignores aspects a pragmatic and central aspect, not an Misapprehensions of clinical training, such as the physical academic or tangential element of op¬ Evidence-Based Medicine examination. timal patient care. The problem select¬ In developing the practice and teach¬ Correction.—Careful history taking ed for critical appraisal must be one that ing of evidence-based medicine at our and physical examination provide much, the learners recognize as important, feel institution, we have found that the na¬ and often the best, evidence for diag¬ uncertain, and do not fully trust expert ture of the new paradigm is sometimes nosis and direct treatment decisions. The opinion; in other words, they must feel misinterpreted. Recognizing the limita¬ clinical teacher of evidence-based med¬ it is worth the effort to find out what the tions of intuition, experience, and un¬ icine must give considerable attention literature says on a topic. The likeliest derstanding of pathophysiology in per¬ to teaching the methods of history tak¬ candidate topics are common problems mitting strong inferences may be mis¬ ing and clinical examination, with par¬ where learners have been exposed to interpreted as rejecting these routes to ticular attention to which items have divergent opinions (and thus there is knowledge. Specific misinterpretations demonstrated validity and to strategies disagreement and/or uncertainty among ofevidence-based medicine and their cor¬ that enhance observer agreement. the learners). The clinical teacher should rections follow: keep these requirements in mind when Misinterpretation 1.—Evidence- Barriers to Teaching considering questions to encourage the based medicine ignores clinical experi¬ Evidence-Based Medicine learners to address. It can be useful to ence and clinical intuition. Difficulties we have encountered in ask all members of the group their opin¬ Correction.—On the contrary, it is teaching evidence-based medicine in¬ ion about the clinical problem at hand. important to expose learners to excep¬ clude the following: One can then ensure that the problem is tional clinicians who have a gift for in¬ 1. Many house staff start with rudi¬ appropriate for a critical appraisal ex¬ tuitive diagnosis, a talent for precise mentary critical appraisal skills and the ercise by asking the group the following observation, and excellent judgment in topic may be threatening for them. questions: making difficult management decisions. 2. People like quick and easy answers. 1. It seems the group is uncertain Untested signs and symptoms should Cookbook medicine has its appeal. Crit¬ about the optimal approach. Is that not be rejected out of hand. They may ical appraisal involves additional time right? prove extremely useful and ultimately and effort and may be perceived as in¬ 2. Do you feel it is important for us to be proved valid through rigorous test¬ efficient and distracting from the real sort out this question by going to the ing. The more the experienced clinicians goal (to provide optimal care for pa¬ original literature? can dissect the process they use in di¬ tients). and it to learn¬ 3. For clinical Criteria agnosis,31 clearly present many questions, high- Methodological ers, the greater the benefit. Similarly, quality evidence is lacking. If such ques¬ Criteria for methodological rigor must the gain for students will be greatest tions predominate in attempts to intro¬ be few and simple. Most published crite¬ when clues to optimal diagnosis and duce critical appraisal, a sense offutility ria can be overwhelming for the novice. treatment are culled from the barrage can result. Suggested criteria for studies of diagno¬ of clinical information in a systematic 4. The concepts of evidence-based sis, treatment, and review articles follow: and reproducible fashion. medicine are met with skepticism by

Downloaded from www.jama.com at Vrije Universiteit on August 22, 2009 many faculty members who are there¬ views meeting scientific principles30,33 tient outcomes may appear to be an in¬ fore unenthusiastic about modifying and collections ofmethodologically sound ternal contradiction. As has been point¬ their teaching and practice in accordance and highly relevant articles14 can mark¬ ed out, however, evidence-based with its dictates. edly increase efficiency. Other solutions medicine does not advocate a rejection These problems can be ameliorated will emerge over time. Health educa¬ of all innovations in the absence of de¬ by use of the strategies described in the tors will continue to find better ways of finitive evidence. When definitive evi¬ previous section on effective teaching of role modeling and teaching evidence- dence is not available, one must fall back evidence-based medicine. Threat can be based medicine. Standards in writing on weaker evidence (such as the com¬ reduced by making a contract with the reviews and texts are likely to change, parison of graduates of two medical residents, which sets out modest and with a greater focus on methodological schools that use different approaches achievable goals, and further reduced rigor.15·16 Evidence-based summaries will cited above) and on biologic rationale. by the attending physician role model¬ therefore become increasingly available. The rationale in this case is that physi¬ ing the practice of evidence-based med¬ Practical approaches to making evi¬ cians who are up-to-date as a function of icine. Inefficiency can be reduced by dence-based summaries easier to apply their ability to read the current litera¬ teaching effective searching skills and in clinical practice, many based on com¬ ture critically, and are able to distin¬ simple guidelines for assessing the va¬ puter technology, will be developed and guish strong from weaker evidence, are lidity of the papers. In addition, one can expanded. As described earlier, we are likely to be more judicious in the ther¬ emphasize that critical appraisal as a already using computer searching on the apy they recommend. Physicians who strategy for solving clinical problems is ward. In the future, the results of di¬ understand the properties of diagnostic most appropriate when the problems are agnostic tests may be provided with the tests and are able to use a quantitative common in one's own practice. Futility associated sensitivity, specificity, and approach to those tests are likely to make can be reduced by, particularly initially, likelihood ratios. Health policymakers more accurate diagnoses. While this ra¬ targeting critical appraisal exercises to may find that the structure of medical tionale appears compelling to us, com¬ areas in which there is likely to be high- practice must be shifted in basic ways to pelling rationale has often proved mis¬ quality evidence that will affect clinical facilitate the practice of evidence-based leading. Until more definitive evidence decisions. Skepticism of faculty mem¬ medicine. Increasingly, scientific over¬ is adduced, adoption of evidence-based bers can be reduced by the availability views will be systematically integrated medicine should appropriately be re¬ of "quick and dirty" (as well as more with information regarding toxicity and stricted to two groups. One group com¬ sophisticated) courses on critical apprais¬ side effects, cost, and the consequences prises those who find the rationale com¬ al of evidence and by the teaching part¬ of alternative courses of action to de¬ pelling, and thus believe that use of the nerships and teaching workshops de¬ velop clinical policy guidelines.34 The evidence-based medicine approach is scribed earlier. prospects for these developments are likely to improve clinical care. A second Many problems in the practice and both bright and exciting. group comprises those who, while skep¬ teaching of evidence-based medicine re¬ tical of improvements in patient out¬ main. both DOES TEACHING AND LEARNING believe it is that Many physicians, including EVIDENCE-BASED MEDICINE come, very unlikely residents and members, are still deterioration in care results from the faculty IMPROVE PATIENT OUTCOMES? skeptical about the tenets of the new evidence-based approach and who find paradigm. A medical residency is full of The proof of the pudding of evidence- that the practice of medicine in the new competing demands, and the appropri¬ based medicine lies in whether patients paradigm is more exciting and fun. ate balance between is not cared for in this fashion better goals always enjoy CONCLUSION evident. At the same time, we are buoyed health. This proof is no more achievable by the number of residents and faculty for the new paradigm than it is for the Based on an awareness of the limita¬ who have enthusiastically adopted the old, for no long-term randomized trials tions of traditional determinants of clin¬ new approach and found ways to inte¬ of traditional and evidence-based med¬ ical decisions, a new paradigm for med¬ grate it into their learning and practice. ical education are likely to be carried ical practice has arisen. Evidence-based out. What we do have are a number of medicine deals directly with the uncer¬ Barriers to Practicing short-term studies which confirm that tainties of clinical medicine and has the Evidence-Based Medicine the skills ofevidence-based medicine can potential for transforming the educa¬ Even if our residency program is suc¬ be taught to medical students35 and med¬ tion and practice of the next generation cessful in producing graduates who en¬ ical residents.36 In addition, a study com¬ of physicians. These physicians will con¬ ter the world of clinical practice enthu¬ pared the graduates of a medical school tinue to face an exploding volume of siastic to apply what they have learned that operates under the new paradigm literature, rapid introduction of new about evidence-based medicine, they will (McMaster) with the graduates of a tra¬ technologies, deepening concern about face difficult challenges. Economic con¬ ditional school. A random sample of burgeoning medical costs, and increas¬ straints and counterproductive incen¬ McMaster graduates who had chosen ing attention to the quality and outcomes tives may compete with the dictates of careers in family medicine were more of medical care. The likelihood that ev¬ evidence as determinants of clinical de¬ knowledgeable with respect to current idence-based medicine can help amelio¬ cisions; the relevant literature may not therapeutic guidelines in the treatment rate these problems should encourage be readily accessible; and the time avail¬ of hypertension than were the gradu¬ its dissemination. able may be insufficient to carefully re¬ ates of the traditional school.37 These Evidence-based medicine will require view the evidence (which may be volu¬ results suggest that the teaching of ev¬ new skills for the physician, skills that minous) relevant to a pressing clinical idence-based medicine may help grad¬ residency programs should be equipped problem. uates stay up-to-date. Further evalua¬ to teach. While strategies for inculcat¬ Some solutions to these problems are tion of the evidence-based medicine ap¬ ing the principles ofevidence-based med¬ already available. Optimal integration proach is necessary. icine remain to be refined, initial expe¬ ofcomputer technology into clinical prac¬ Our advocating evidence-based med¬ rience has revealed a number of effec¬ tice facilitates finding and accessing ev¬ icine in the absence of definitive evi¬ tive approaches. Incorporating these idence. Reference to literature over- dence of its superiority in improving pa- practices into postgraduate medical ed-

Downloaded from www.jama.com at Vrije Universiteit on August 22, 2009 ucation and continuing to work on their partment of Medicine, McMaster University; Allan tize Cardio-Vasculaires, Paris, France; Virginia further will result in more Detsky, MD, PhD, Department of Clinical Epide¬ Moyer, MD, Department of Pediatrics, University development miology and Biostatistics, McMaster University of Texas, Houston; Cynthia Mulrow, MD, Depart¬ rapid dissemination and integration of and Departments of Health Administration and ment of Medicine, University of Texas, San Anto¬ the new paradigm into medical practice. Medicine, University of Toronto (Ontario); Murray nio; Paul Links, MD, MSc, Department of Psychi¬ Enkin, MD, Departments of Clinical Epidemiology atry, McMaster University; Andrew Oxman, MD, The Evidence-Based Medicine Working Group and Biostatistics and Obstetrics and Gynaecology, MSc, Departments of Clinical Epidemiology and comprised the following: Gordon Guyatt (chair), McMaster University; Pamela Frid, MD, Depart¬ Biostatistics and Family Medicine, McMaster Uni¬ MD, MSc, John Cairns, MD, David Churchill, MD, ment of Pediatrics, Queen's University, Kingston, versity; Jack Sinclair, MD, Departments of Clinical MSc, Deborah Cook, MD, MSc, Brian Haynes, MD, Ontario; Martha Gerrity, MD, Department of Med¬ Epidemiology and Biostatistics and Pediatrics, MSc, PhD, Jack Hirsh, MD, Jan Irvine, MD, MSc, icine, University of North Carolina, Chapel Hill; McMaster University; and Peter Tugwell, MD, Mark Levine, MD, MSc, Mitchell Levine, MD, MSc, Andreas Laupacis, MD, MSc, Department of Clin¬ MSc, Department of Medicine, University of Ot¬ Jim Nishikawa, MD, and David Sackett, MD, MSc, ical Epidemiology and Biostatistics, McMaster tawa (Ontario). Departments of Medicine and Clinical Epidemiol¬ University and Department of Medicine, Univer¬ Drs Cook and Guyatt are Career Scientists of ogy and Biostatistics, McMaster University, sity of Ottawa (Ontario); Valerie Lawrence, MD, the Ontario Ministry of Health. Dr Haynes is a Na¬ Hamilton, Ontario; Patrick Brill-Edwards, MD, Department of Medicine, University of Texas tional Health Scientist, National Health Research Hertzel Gerstein, MD, MSc, Jim Gibson, MD, Ro¬ Health Science Center at San Antonio and Audie L. and Development Program, Canada. Drs Jaeschke man Jaeschke, MD, MSc, Anthony Kerigan, MD, Murphy Memorial Veterans Hospital, San Antonio, and Cook are Scholars of the St Joseph's Hospital MSc, Alan Neville, MD, and Akbar Panju, MD, De- Tex; Joel Menard, MD, Centre de Medicine Trezen- Foundation, Hamilton, Ontario.

References 1. Lindberg DA. Information systems to support 13. Haynes RB, Mulrow CD, Huth EJ, Altman DG, ings. In: Clayton PD, ed. Proceedings of the Fifth medical practice and scientific discovery. Methods Gardner MJ. More informative abstracts revisited. Annual Symposium on Computer Applications in Inform Med. 1989;28:202-206. Ann Intern Med. 1990;113:69-76. Medical Care, November 1991; Washington, DC. 2. Hart YM, Sander JW, Johnson AL, Shorvon SD. 14. Haynes RB. The origins and aspirations of ACP New York, NY: McGraw-Hill International Book National general practice study of epilepsy: recur- Journal Club. Ann Intern Med. 1991;114(ACP J Co; 1992:73-77. rence after a first seizure. Lancet. 1990;336:1271\x=req-\ Club. suppl 1):A18. 27. Laupacis A, Sackett DL, Roberts RS. An as- 1274. 15. Chalmers I, Enkin M, Keirse MJNC, eds. Ef- sessment of clinically useful measures of the con- 3. Sackett DL, Haynes RB, Guyatt GH, Tugwell P. fective Care in Pregnancy and Childbirth. New sequences of treatment. N Engl J Med. 1988;318: Clinical Epidemiology: A Basic Science for Clini- York, NY: Oxford University Press Inc; 1989. 1728-1733. cial Medicine. 2nd ed. Boston, Mass: Little Brown 16. Sinclair JC, Braken MB, eds. Effective Care of 28. Department of Clinical Epidemiology and Bio- & Co Inc; 1991:173-186. the Newborn Infant. New York, NY: Oxford Uni- statistics, McMaster University. How to read clin- 4. Kuhn TS. The Structure of Scientific Revolu- versity Press Inc; 1992. ical journals, II: to learn about a diagnostic test. tions. Chicago, Ill: University of Chicago Press; 17. Audet AM, Greenfield S, Field M. Medical prac- Can Med Assoc J. 1981;124:703-710. 1970. tice guidelines: current activities and future direc- 29. Department of Clinical Epidemiology and Bio- 5. European Carotid Surgery Trialists' Collabora- tions. Ann Intern Med. 1990;113:709-714. statistics, McMaster University. How to read clin- tive Group. MRC European Carotid Surgery Trial: 18. Guyatt GH. Evidence-based medicine. Ann In- ical journals, V: to distinguish useful from useless interim results for symptomatic patients with se- tern Med. 1991;114(ACP J Club. suppl 2):A-16. or even harmful therapy. Can Med Assoc J. 1981; vere (70-99%) or with mild (0-29%) carotid stenosis. 19. Light DW. Uncertainty and control in profes- 124:1156-1162. Lancet. 1991;337:1235-1243. sional training. J Health Soc Behav. 1979;20:310\x=req-\ 30. Oxman AD, Guyatt GH. Guidelines for reading 6. Larsen ML, Horder M, Mogensen EF. Effect of 322. literature reviews. Can Med Assoc J. 1988;138:697\x=req-\ long-term monitoring of glycosylated hemoglobin 20. Chalmers I. Scientific inquiry and authoritar- 703. levels in insulin-dependent diabetes mellitus. NEngl ianism in perinatal care and education. Birth. 1983; 31. Campbell EJM. The diagnosing mind. Lancet. J Med. 1990;323:1021-1025. 10:151-164. 1987;1:849-851. 7. L'Abbe KA, Detsky AS, O'Rourke K. Meta-anal- 21. Cassell EJ. The nature of suffering and the 32. Feinstein AR. What kind of basic science for ysis in clinical research. Ann Intern Med. 1987;107: goals of medicine. N Engl J Med. 1982;306:639-645. clinical medicine? N Engl J Med. 1970;283:847-853. 224-233. 22. Ende J, Kazis L, Ash A, Moskowitz MA. Mea- 33. Mulrow CD. The medical review article: state 8. Ransohoff DF, Feinstein AR. Problems of spec- suring patients' desire for autonomy: decision-mak- of the science. Ann Intern Med. 1987;106:485-488. trum and bias in evaluating the efficacy of diag- ing and information-seeking preferences among 34. Eddy DM. Guidelines for policy statements: the nostic tests. N Engl J Med. 1978;299:926-930. medical patients. J Gen Intern Med. 1989;4:23-30. explicit approach. JAMA. 1990;263:2239-2243. 9. Nierenberg AA, Feinstein AR. How to evaluate 23. Carter WB, Inui TS, Kukull WA, Haigh VH. 35. Bennett KJ, Sackett DL, Haynes RB, et al. A a diagnostic market test: lessons from the rise and Outcome-based doctor-patient interaction analysis. controlled trial of teaching critical appraisal of the fall ofdexamethasone suppression test. JAMA. 1988; Med Care. 1982;20:550-556. clinical literature to medical students. JAMA. 1987; 259:1699-1702. 24. Greenfield S, Kaplan S, Ware JE Jr. Expanding 257:2451-2454. 10. Haynes RB, McKibbon KA, Fitzgerald D, patient involvement in care: effects on patient out- 36. Kitchens JM, Pfeifer MP. Teaching residents to Guyatt GH, Walker CJ, Sackett DL. How to keep comes. Ann Intern Med. 1985;102:520-528. read the medical literature: a controlled trial of a up with the medical literature, V: access by per- 25. Haynes RB, McKibbon A, Walker CJ, Ryan N, curriculum in critical appraisal/clinical epidemiol- sonal computer to the medical literature. Ann In- Fitzgerald D, Ramsden ME. Online access to MED- ogy. J Gen Intern Med. 1989;4:384-387. tern Med. 1986;105:810-816. LINE in clinical settings: a study of use and use- 37. Shin J, Haynes RB. Does a problem-based, self- 11. Bulpitt CJ. Confidence intervals. Lancet. 1987; fulness. Ann Intern Med. 1990;112:78-84. directed undergraduate medical curriculum pro- 1:494-497. 26. McKibbon KA, Haynes RB, Johnston ME, mote continuing clinical competence? Clin Res. 1991; 12. Godfrey K. Simple linear regression in medical Walker CJ. A study to enhance clinical end-user 39:143A. research. N Engl J Med. 1985;313:1629-1636. MEDLINE search skills: design and baseline find-

Downloaded from www.jama.com at Vrije Universiteit on August 22, 2009