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Evidence-Based Medicine:
White Knight or Ivory Tower? |
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By Tamar Hosansky, Editor, Medical Meetings Magazine
MONTREAL—Expert recommendations are often disastrously wrong and can turn out to kill patients when tested in randomized trials, declared Gordon Guyatt, MD, MSc, Professor, Clinical Epidemiology and Biostatistics and Medicine, McMaster University, Ontario, Canada. In a hard-hitting and impassioned plenary presentation, Dr. Guyatt laid out the case for teaching physicians to make decisions predicated on evidence-based medicine.
He began with a background of how the concept of evidence-based medicine was developed. He and his colleagues needed evidence that expert recommendations had limitations. They studied the history of the numerous clinical trials studying the effect of thrombolytic therapy for preventing deaths in patients who suffer from myocardial infarction. "By the time 27 trials were completed with 6,000 patients enrolled, we could be pretty confident that thrombolytic therapy reduces death rates after myocardial infarction by about 25 percent. Did this stop people from conducting randomized trials in which patients received thrombolytic therapy or a placebo or no treatment? No, it did not. Forty thousand additional patients were enrolled in clinical trials, one-half of whom did not receive the benefits of the therapy and were subjected to unnecessary risks. [Those trials] also devoted research resources that could have been better spent elsewhere after the answer was in," said Dr. Guyatt.
He also pointed out that expert recommendations during the time period of the clinical trials ranged from saying thrombolytic therapy should be administered routinely to saying it was an experimental treatment to not even mentioning it at all. "The lag between the time the evidence was in and the time everybody started agreeing that thrombolytic therapy should be offered was about a decade," noted Dr. Guyatt.
Another disturbing example was about clinical trials studying the effect of prophylactic lidocaine in treatment of myocardial infarction. The results showed that the therapy increased the risk of death. "Did this stop the experts from recommending lidocaine?" Dr. Guyatt asked. "No, it did not. Most of the time—despite no evidence—everybody was saying this is good stuff." Clearly, Dr. Guyatt concluded, "there was something wrong with the way we were adopting expert recommendations and perhaps alternatives should be considered."
The alternative is the evidence-based medicine pyramid, Dr. Guyatt explained, which starts with systematic reviews and meta-analyses of randomized clinical trials. "If you don't have that available, you fall back on individual randomized trials, and only when that is not available do you go to observational studies, basic research, or clinical experience," he stated. If physicians are to rely on evidence-based medicine, they need to learn skills that are not traditionally taught in medical schools and residency programs. They have to learn how to efficiently search for the evidence and how to appraise that evidence, he added.
Finally, physicians need to be able to apply the evidence to patient care. "Evidence itself never tells you what to do," said Dr. Guyatt. "It's always evidence plus values and preferences."
Those values and preferences can differ among cultures. "Let me tell you about a 95-year-old patient with pneumococcal pneumonia," Dr. Guyatt told the audience. "She has severe dementia, she hasn't recognized anybody in five years, nor has anybody come to visit her. She can't straighten her arms and legs, she is incontinent of urine and feces, and she moans in apparent pain from morning to night. How many people think it would be a good idea if she got antibiotics?" One person responded yes. "When I give this test to audiences of 100 people, two or three people will put up their hands and say, 'yes,'" Dr. Guyatt continued. But those are U.S. audiences. "I was in Chile last week and 50 % of the audience said 'yes.' What does this illustrate? That the divergence in our opinions is not because of any difference in opinion about the evidence for therapy for pneumococcal pneumonia, but has to do with values and preferences as they differ across cultures." In Chile, because of its strong Catholic culture, people put a higher value on preserving human life even in the face of extreme suffering and loss of dignity, Dr. Guyatt explained. The Chileans might say they see dignity and value in the preservation of human life even in the face of suffering. Healthcare decisions are value laden, and never rely exclusively on evidence.
EBM: A Reality Check
Your phone rings at 3 a.m. A parent is on the phone asking for help with her child's ear infection. In the background, you hear the child screaming. What do you do? The guidelines say to treat the child symptomatically for fever and pain; and not to prescribe antibiotics unless symptoms persist beyond 24 hours. But faced with a pleading, exhausted parent and screaming child, are you really going to say "Take two aspirin and call me in the morning." This is one example of the numerous real-life barriers primary care physicians face in implementing evidence-based medicine, said Richard Ward, MD, CCFP, FCFP, MAINPRO-C Coordinator, CME & Professional Development, University of Calgary.
Evidence-based CME should address those barriers and answer problems that physicians see in practice, Dr. Ward said. "It should be facilitative, rather than create more barriers to care." EB-CME should also incorporate adult learning principles, he said. For instance, instead of issuing a handout on how to treat otitis media, providers should set up a series of small group workshops on the difficulties or challenges involved, including a scenario such as the one described above. That approach, said Ward, enables physicians to see how evidence-based medicine helps them solve problems they currently face in their practice.
"Physicians should walk out from learning experiences feeling grounded, feeling that they can do things better, rather than feeling that they have to do these things," Dr. Ward said.
EBM: the Pharma Perspective
Offering industry's perspective on evidence-based medicine, Céline Monette, BSc, Director of Scientific Communications and Professional Education, Aventis Pharma, Montréal, Québec; and Co-chair, Continuing Health Education Working Group, Canada's Research Based Pharmaceutical Companies, said that one of the barriers to implementing evidence-based medicine is the pharmaceutical industry's lack of knowledge about it.
Monette stated that it is crucial for CME providers and pharma companies to collaborate. The pharmaceutical industry is interested, she said, in partnering in the dissemination of evidence and guidelines, as well as in educating health professionals and consumers.
She also discussed the patient's perspective. While patients are more aware of evidence now, Monette said, there are barriers to patient adherence. For instance, if guidelines say a certain test is warranted, the test may not be available in the patient's area. There also needs to be more work done in improving patient/healthcare provider relationships, she concluded.
Putting Evidence-based CME into Practice
Taking a leadership role in the shift towards evidence-based medicine, the American Academy of Family Physicians (AAFP) became the first organization in the U.S. to develop a system for accrediting evidence-based CME. Launched in January 2002 after a pilot period in 2001, the AAFP initiative gives providers the option to apply for evidence-based credit for their activities. [Editor's Note: Unlike the Accreditation Council for Continuing Medical Education (ACCME), the AAFP accredits activities, not providers.]
The AAFP established the new criteria in part because of concerns expressed by the Federation of State Medical Boards and other organizations about complementary and alternative practice topics in CME, said Nancy Davis, PhD, Director, Division of CME, AAFP, Leawood, Kansas. Under the new system, activities about complementary and alternative practice are eligible for elective credit only, not for prescribed credit.
The AAFP's initiative is part of a national trend. It was developed in collaboration with other major organizations, including the American Board of Family Practice, the ACCME, the American Medical Association, the American Osteopathic Association, and the Federation of State Medical Boards. Following the AAFP's lead, the ACCME has also developed a new policy to ensure content validity.
For other providers considering implementing evidence-based CME, Dr. Davis had this advice: begin with topics that lend themselves to evidence-based medicine, work with faculty who understand it, and remember that courses can be mixed, comprising both evidence-based and non evidence-based material. |
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