Evidence Based Medicine

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,,,,, G U EST EDITORIAL,,,,, The Society of Obstetricians and Gynaecologists of Canada COUNCIL MEMBERS 1996-1997 PRESIDENT: Dr.

Garry Krepart - Winnipeg PRESIDENT ELECT: Dr

Andre B Lalonde - Ottawa ASSOCIATE EXECUTIVE VICE-PRESIDENT' Dr Robert Kinch - Ottawa TREASURER: Dr Antonln Rochette - Loretteville VICE PRESIDENTS: Dr Thomas Baskett - Halifax Dr Robert Gauthler -

1 ,,,,, G U EST EDITORIAL,,,,, The Society of Obstetricians and Gynaecologists of Canada COUNCIL MEMBERS PRESIDENT: Dr. Nan Schuurmans - Edmonton PAST PRESIDENT' Dr Garry Krepart - Winnipeg PRESIDENT ELECT: Dr Robert Reid - Kingston EXECUTIVE VICE-PRESIDENT. Dr. Andre B Lalonde - Ottawa ASSOCIATE EXECUTIVE VICE-PRESIDENT' Dr Robert Kinch - Ottawa TREASURER: Dr Antonln Rochette - Loretteville VICE PRESIDENTS: Dr Thomas Baskett - Halifax Dr Robert Gauthler - Montreal REGIONAL CHAIRS & DEPUTY CHAIRS WESTERN REGION Dr Jan Christilaw - White Rock Dr. Donald Davls - Medicine Hat CENTRAL REGION Dr Chui Kin Yuen - Winnipeg Dr. Th,rza Smith - Saskatoon ONTARIO REGION Dr Donna Fedorkow - Hamilton Dr. Catherine Claire Kane - Ottawa QUEBEC REGION Dr. Cajetan Gauthier - Levis Dr. Vyta Senikas - Montreal ATLANTIC REGION Dr David A. Knlckle - Charlottetown Dr Garth Christie - Fredericton PUBLIC REPRESENTATIVE Ms. Janet MacMillan - Halifax JUNIOR FELLOW REPRESENTATIVE Dr. Robert Krushel - St. John's ASSOCIATE MD REPRESENTATIVE Dr T Riley - Oakville ASSOCIATE NURSING REPRESENTATIVE Ms Marie-Josee Trepanier - Ottawa NATIONAL OFFICE EXECUTIVE VICE-PRESIDENT Dr Andre B Lalonde DIRECTOR OF COMMUNICATIONS Martlne Joly 774 Echo Drove Ottawa, Ontaroo K1S5N8 tel: (613) or fax: (613) Evidence Based Medicine As clinicians, we are constantly confronted by a growing body of medical information, the quality of which varies considerably from mostly poor to occasionally excellent. This information base is often relied upon to help us to answer questions we regularly face about the efficacy of a particular therapy or disease preventive strategy, the accuracy and interpretation of a diagnostic test, the effect associated with exposure to a putatively harmful agent, the course and prognosis of disease in a specific patient, and the costeffectiveness of a new intervention. However, before such information can be used to help us in maximizing the care we provide our patients, it has to be evaluated to determine its validity and relevance to clinical care. Salim Daya, MB, MSc, Professor, Departments of Obstetrics and Gynaecology and Clinical Epidemiology and Biostatistics, McMaster University Unfortunately, the demands of a busy practice make it increasingly difficult to keep abreast of the field of medicine, especially when there are presently at least 19 new articles available daily to general physicians.' Even enthusiastic academic physicians spend only a few hours a week trying to keep up with new information, much of which is not valid or relevant to clinical practice. Consequently, our management decisions, by and large, are based on our original clinical training or on unsystematic observations from our clinical experiences with individual patients. These experiences, together with an understanding of the basic pathophysiologic mechanisms of diseases, have led us to develop a level of familiarity that has been considered sufficient to enable guidelines for clinical care to be formulated. Such clinically derived expertise should be interpreted cautiously in light of the inverse correlation that exists between our knowledge of up-to-date care and the length of time that has lapsed since our graduation from medical school. This sobering fact was vividly demonstrated in a study of hypertension in which the decision to initiate therapy was more closely linked to the number of years since the physician's graduation than to the severity of the patient's disease. 2 A new paradigm in medicine has emerged and is gaining popularity in its ability to assist physicians in their decision making challenges. This approach places less emphasis on intuition, clinical experiences obtained in a nonsystematic manner, and pathophysiologic rationale as being sufficient grounds JOURNAL SOGC 851 SEPTEMBER 1996

2 The less chemical impact an OC has on her body, the better. That's why it makes sense to prescribe TRI-CYCLEN* (with norgestimate and ethinyl estradiol). An OC with low hormonal impact. An OC with low hormonal blends with

t So whether they're new starts or restarts, most women who start on TRI-CYCLEN stay on TRI -CYCLEN.

3 TRI-CYCLEN contains the low activity selective progestin norgestimate, in a phased low dose for low overall hormonal impact. 1 2 Plus, TRI-CYCLEN is more than 99% effective.t So whether they're new starts or restarts, most women who start on TRI-CYCLEN stay on TRI -CYCLEN. 1 t Pearl index o( I.36 impact that nature's cycle. Norgestimate/ethlnyl estradiol ~ Cycle n Effective low impact contraception

4 ,,, for making clinical decisions, but instead supports clinical practice on the strength of evidence from clinical research.) It is becoming increasingly evident that clinical research is not a luxury but is essential to problem solving across the entire range of health care activities. 4 Clinical research is equally important to, but not in conflict with, basic research, which is driven by curiosity to produce work of high quality and innovativeness. In fact, we depend on this type of speculative research to advance our understanding of disease processes. But research that is directed towards providing clinical care more effectively and efficiently is especially important in the present era of rapidly expanding technology and shrinking health care budgets. The new paradigm, referred to as evidence based medicine, does not stress that identification of a clinical problem should provoke an immediate response of commissioning research to address the problem. Instead, the first step should be to determine if the problem can be tackled using existing research findings. Such information has to be sought and evaluated, using formal rules for the critical appraisal of clinical research evidence. This approach is the foundation of the science of evidence based medicine, which is defined as the conscientious, explicit, and judicious use of the best evidence that is currently available to make decisions about the care of individual patients. \ The best of the relevant studies in the literature are selected after subjecting each one to validity assessment. The clinical data are extracted and summarized so that a succinct solution can be provided for the clinical problem at hand. This critical appraisal exercise requires special skills that have not been part of traditional medical thinking, but can be learned quickly. Although this approach de-emphasizes the value of medical expertise, it does not reject the importance of such time-honoured skills of medical training as history taking, physical examination, and diagnostic strategies. In fact, it is the proficiency that clinicians acquire through clinical experience and understanding mechanisms of disease that prepares them better to apply the results of the critical appraisal exercise to the clinical problems posed by their patients. Thus, the practice of evidence based medicine requires the integration of clinical skills with the best available evidence from systematic research that is clinically relevant. It is the absence of this integration that is responsible for the practice of medicine becoming quickly out of date and of little benefit to patients. Clinical evidence augments, but does not replace, clinical experience in deciding whether the evidence applies to individual patients and how it should be incorporated into a management plan to maximize the benefit to them. The question of whether the practice of evidence based medicine improves patient outcome is difficult to answer without randomized trials comparing it to the traditional, opinion-based approach. Such trials are unlikely to be conducted without the risk of contamination, whereby those allocated to the traditional approach become exposed to concepts from the new approach. Nevertheless, there are results from trials which indicate that evidence based medicine can be taught effectively to medical students and residents Also, the results from another study suggested that teaching evidence based medicine may help graduates to stay up-to-date. 8 This study, using an ecological design, compared graduates from McMaster University Medical School, which provides instruction using the new paradigm, with those from the traditional school. Similarly, the findings from another study demonstrated that graduates of a medical school that teaches lifelong, selfdirected, evidence based medicine are still up to date as long as 15 years after graduation. 9 The gold standard for the study design that produces superior quality evidence is the randomized trial which also forms the basis of meta-analysis, an increasingly popular method of analysing data from multiple trials. The importance of meta-analysis can be seen in our specialty with the publication of Effective Care in Pregnancy and Childbirth,lO a compendium of overviews and metaanalyses in obstetrics that has enabled us to review our management options based on the available evidence. For some clinical situations, the analyses have reassured us that our strategies are appropriate, but for many others the data suggest that our therapies should be re-evaluated. Recently, a landmark trial of anti-convulsant therapy for eclampsia emphasized this point further by demonstrating that magnesium sulphate has clear advantages over both phenytoin and diazepam,u The tragedy here is that we had to wait for 70 years to obtain the answer to the clinical question of the most appropriate therapy, a problem which has been debated by obstetricians around the world. Various drugs and drug cocktails have been recommended by avid proponents, without strong evidence supporting their assertions. In fact, since 1987 many JOURNAL SOGe 854 SEPTEMBER 1996

5 ,,, poorly controlled studies have been published "supporting" the use of phenytoin, not only for the treatment of eclamptic convulsions but also for its prophylaxis. The interest in evidence based medicine has led to the establishment of several other resources to which the busy practitioner can have easy access. The International Cochrane collaboration is developing a data base of randomized trials in all areas of medicine so that metaanalyses directed towards answering specific clinical questions can be conducted. The resulting overviews will become available as they are completed, and will add to the information that physicians will have to obtain in deciding on the best care for their patients. Another resource in this field is the publication of evidence based medicine summaries in a newly established journal called Evidence Based Medicine, which is produced in collaboration with its related publication, ACP Journal Club. Each month, over 50 journals are screened for articles on diagnosis, prognosis, therapy, aetiology, quality of care, and health economics that are both relevant to medical practice and also adhere to rigorous methodological standards for patient-based research. A selection of articles that satisfy the screening criteria is summarized and placed in proper clinical context by an accompanying commentary from a content expert. Our specialty will continue to face an explosion in the volume of medical literature, rapid introduction of new technologies, rationalization of health care resources, and increasing attention to the quality and outcomes of medical care. It is incumbent upon us to acquire the skills necessary to appraise the literature critically so that the best quality evidence can be selected and applied to managing our patients' problems. These skills should also be taught in residency programmes so that the concepts of good clinical practice and good clinical research become completely integrated and form the basis for effective and appropriate clinical decision making. We have entered a new era of medical practice that requires us to learn these new skills. We should rise to this challenge without any hesitation because it will enable us to serve our patients better. 3. Evidence-based medicine working group. Evidencebased medicine. A new approach to teaching the practice of medicine. JAMA 1992: 268: Smith R. Filling the lacuna between research and practice: an interview with Michael Peckham. Br Med J 1993; 307: Sackett DL, Rosenberg WMC, Gray JAM, Haynes RB, Richardson WS. Evidence-based medicine: what it is and what it isn't. Br Med J 1996; 312: Bennett KJ, Sackett DL, Haynes RB, Neufeld VR. A controlled trial of teaching critical appraisal of the clinical literature to medical students. JAMA 1987; 257: Kitchens JM, Pfeifer MP. Teaching residents to read the medical literature: a controlled trial of a curriculum in critical appraisal/clinical epidemiology. J Gen Intern Med 1989; 4: Shin J, Haynes RB. Does a problem-based, self-directed undergraduate medical curriculum promote continuing clinical competence? Clin Res 1991; 39:143A. 9. Shin JH, Haynes RB, Johnston ME. The effect of problembased, self directed undergraduate education on lifelong learning. Can Med AssocJ 1993; 148: Chalmers I, Enkin M, Keirse MJNC (Eds). Effective Care in Pregnancy and Childbirth. New York, NY, Oxford University Press Inc, The Eclampsia Collaborative Group. Which anti-convulsant for women with eclampsia? Evidence from the Collaborative Eclampsia Trial. Lancet 1995; 345: REFERENCES J SOGe 1996;18: Davidoff F, Haynes B, Sackett D, Smith R. Evidence based medicine. A new journal to help doctors identify new information they need. Br Med J 1995; 310: Evans CE, Haynes RB, Gilbert JR, Taylor DW, Sackett DL, Johnston M. Educational package on hypertension for primary care physicians. Can Med Assoc J 1984; 130: JOURNALSOGC 855 SEPTEMBER1996

Evidence based practice: Colorectal cancer nursing perspective

Evidence based practice: Colorectal cancer nursing perspective Professor Graeme D. Smith Editor Journal of Clinical Nursing Edinburgh Napier University China Medical University, August 2017 Editor JCN