|
|
楼主 |
发表于 2015-8-28 07:47
|
显示全部楼层
[JAMA]: 你需要了解的循证医学（英文）
2015年05月19日 ⁄ 临床话题, 基本知识 ⁄ 暂无评论
[编者按]：在过去十年间，循证医学一直是临床医生关注的焦点。有人对它奉若神明，也有人对它不屑一顾。2015年5月12日，JAMA发表了对循证医学最初的倡导者，加拿大多伦多McMaster大学Gordon Guyatt医生的访谈。让我们看看他对于循证医学的理解。不久我们还将发布本文的中文译文。
Medical News & Perspectives | May 12, 2015
Everything You Ever Wanted to Know About Evidence-based Medicine
Rebecca Voelker, MSJ
JAMA. 2015;313(18):1783-1785. doi:10.1001/jama.2015.2845.
m_jmn150013fa
Gordon Guyatt, MD, MSc, McMaster University
What’s in a name? Just ask Gordon Guyatt, MD, MSc. Twenty-five years ago, when he took over as residency director of the internal medicine program at McMaster University in Hamilton, Ontario, Canada, Guyatt wanted to teach resident physicians how to find the best clinical evidence in the medical literature, interpret it correctly, and practice it with patients. “It was something very new at the time,” he says.
To spread the word and appeal to Canadian medical school graduates, he needed a simple label for the approach. He suggested the term “scientific medicine” during a Department of Medicine meeting. “The folks at the meeting, particularly the basic scientists, were outraged,” he recalls. They certainly weren’t teaching unscientific medicine, they protested, and the basic scientists already considered their work to be scientific medicine. So Guyatt needed a new name.
Back at the drawing board, he came up with “evidence-based medicine.” He encountered no backlash and the name stuck. “It proved a remarkably good choice,” Guyatt says.
The term was first published in the American College of Physicians’ Journal Club in 1991 and then in JAMAthe following year. In 1993, an ongoing series called the Users’ Guides to the Medical Literature was launched in JAMA. The series gave rise in 2002 to the first edition of a book with the same name and an added descriptor: A Manual for Evidence-based Clinical Practice. The second edition appeared in 2008, and earlier this year the third edition was published.
Guyatt, distinguished professor of clinical epidemiology and biostatistics and of medicine at McMaster and principal editor of the books, recently spent time with JAMA to discuss updates in the newest edition. An edited version of the conversation follows.
JAMA:Why was an update to the Users’ Guides needed at this time?
Dr Guyatt:It had been 6 years since the previous edition, and we had published a number of new Users’ Guides addressing current and emerging issues in the medical literature. We wanted to include these in a new book, and there were some chapters where real changes or advances had been made in the methodology that we wanted to incorporate as well.
JAMA:Could you describe those advances?
Dr Guyatt:One is noninferiority trials. In traditional clinical trials, you have a new treatment that you think reduces deaths or strokes or heart attacks or improves quality of life. More recently, new treatments have been introduced not because they have good effects on those primary outcomes, but rather because they have other benefits: reducing side effects, being more convenient, or reducing burden. For example, novel anticoagulants were introduced not because they reduce strokes or other thrombotic events, but because they don’t have the monitoring and drug-interaction problems that you see with warfarin. With these new treatments comes a new design for clinical trials. We try not to show that the new drugs are better, but that they’re not too much worse. These have been called noninferiority trials, and they raise new challenges in interpreting and understanding treatment for the condition. Quality improvement also is a big issue now in medicine. Trials are appearing about quality improvement or quality assurance, procedures, and initiatives. So we have a chapter that deals with the critical appraisal and the use of studies about quality improvement. Another emerging area of which there are now many studies are genetic association studies examining whether particular genes are associated with bad outcomes or with the development of conditions, like genes that may be associated with the development of Alzheimer disease. We have a chapter in the new book on these kinds of studies. Other new chapters address additional important advances: one chapter covers shared decision making between patients and clinicians, which more and more is becoming an important part of evidence-based clinical practice. And there are 2 chapters on systematic reviews and meta-analyses. The first of these chapters defines the difference between a systematic review and a meta-analysis and explains how to judge the trustworthiness of the systematic review meta-analytic processes. As we note, a systematic review is a summary of research from different studies that addresses a focused clinical question in a systematic, reproducible manner, and this may be accompanied by a meta-analysis, which is a statistical pooling or aggregation of results from different studies to provide a single best estimate of effect of a therapy, prognosis, or diagnostic test. The second chapter explains how to trust and apply the results of systematic reviews and meta-analyses. Those are some of the major changes that really enhance the value of the Users’ Guides.
JAMA:The new edition also includes a chapter on network meta-analysis. Why is that important?
Dr Guyatt:Typically, treatments for a particular condition have been compared to placebo or 1 drug to another. But there may be 6 or even a dozen drugs available for that condition. How does the clinician choose? In the last decade, a new statistical approach, the network meta-analysis, has been developed. It allows the simultaneous comparison of A vs B vs C vs D vs E vs F, and so on. In the new book, we explain the concept of network meta-analysis and how the clinician can interpret these analyses. Many, many have been published very quickly just in the last several years. Clinicians are going to see them more and more, so they need a Users’ Guide.
JAMA:Which chapter do you think clinicians will find most useful when they’re looking for answers?
Dr Guyatt:An important change in the existing chapters is on finding the evidence—searching for the best evidence to answer your question. Historically we sent people to Medline for individual articles, but what we suggest now is to look first for preprocessed evidence in advanced medical texts, summaries, practice guidelines, and online clinical reference tools like DynaMed, Clinical Evidence, InfoRetriever, and PDxMD. We are now providing guidance for how to quickly and efficiently access and interpret high-quality preprocessed evidence. If these sources fail, you can still go on to more traditional resources like a Medline search. Another tool that has revolutionized ways to find evidence is updating services that send notices of new and exciting things happening in your field. Many are free and they provide regular updates on what is new in your area of practice.
JAMA:President Obama recently announced a new precision medicine initiative to study how genes, health, and the environment are linked. What role can evidence-based medicine play in this initiative?
Dr Guyatt:What evidence-based medicine will do is help people exercise the appropriate caution in using the results of ongoing studies. Just because a gene is associated with an outcome does not mean that everybody needs to be tested for it or that the information is going to be valuable. There’s a lot of exciting potential around genetic testing and using the information in terms of guiding our diagnostic and therapeutic approaches. But there’s also a lot of potential for wasted resources and even for harm. So the relation with evidence-based medicine is that if you understand the principles of evidence-based medicine, you are going to be able to distinguish between new tests or procedures or diagnostic strategies that improve patient outcomes and those that simply use up resources with no benefit and possible harm.
JAMA:How well do you think US medical schools and those in other countries are doing in teaching evidence-based medicine?
Dr Guyatt:Better and better, but still a long way to go. For the last 4 years, I have been chairing a panel that is bringing evidence-based medicine questions to the United States Medical Licensing Examination. We are using an innovative approach. Instead of asking knowledge questions, we present abstracts like those in the American College of Physicians’ Journal Club—good, preprocessed evidence. Then we ask questions about the test takers’ interpretation to see if they understand it. The results are not always terribly encouraging, so we try to keep our questions reasonably simple and straightforward. But from the results we are getting, we have to make them even simpler and more straightforward. This tells us that the concepts of evidence-based medicine for many medical schools either are not a high priority or are not being taught optimally. Sometimes what is being tested drives curriculum, so the fact that these are now appearing on the exam may heighten the profile of teaching evidence-based medicine concepts in US medical schools.
JAMA:Along similar lines, can you gauge how well physicians are practicing evidence-based medicine?
Dr Guyatt:There are very few studies that really tell us about that, so my responses are based only on anecdotes and very low-quality evidence. Having said that, I think it’s better in younger clinicians who have at least had some training in this area and are perhaps more vividly aware of its importance. We hope that even if clinicians are not necessarily aware of evidence-based principles and how to use them to assess the literature themselves, they will still use evidence-based guidelines that lead to evidence-based practice.
JAMA:Evidence-based medicine once was criticized as “cookbook medicine.” Do you still encounter that kind of criticism, and if so, how do you counter it?
Dr Guyatt:One of my favorite talks to give is that evidence-based medicine is patient-centered medicine, so there are a number of things to point out. Perhaps most important is that evidence itself never tells you what to do, never. It’s always evidence in the context of values and preferences. In other words, a person with one set of values and preferences will say, “Yes, it’s the right thing.” Another informed individual would say, “No. For me, the undesirable consequences outweigh the desirable consequences.” Evidence-based medicine has highlighted the fact that so often decisions are value and preference sensitive. To do the best for the individual patient, you need to take into account their values and preferences, ideally in the context of shared decision making. |
|
发表于 2015-8-28 07:45
