[JAMA]: 你需要了解的循证医学（中文）

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[JAMA]: 你需要了解的循证医学（中文）

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

循证医学意味着什么？问问Gordon Guyatt医生。25年前Guyatt开始担任加拿大安大略省Hamilton的McMaster大学内科主任，他希望教会住院医生如何在医学文献中发现最佳临床证据，如何正确解读，并用之于患者。“在当时，这是非常新 的想法，” 他说到。

为在加拿大的医学院毕业生中进行理念的传播，他需要一个简单的名词。在一次内科会议中他建议使用“科学医学”(scientific medicine)一词。“与会的其他人，尤其是从事基础研究的科学家非常愤怒，” 他回忆道。这些人辩解到，自己当然没有在教授非科学医学，而且基础医学的科学家已经认为自己的工作就是科学医学。因此，Guyatt需要想出一个新的名字。

回到画板前，他突然想到“循证医学”。这次他没有遇到强烈反对，因此这个名词就保留下来。 “后来证实这是一个绝好的选择，” Guyatt谈到。

这个名词首先发表在1991年的American College of Physicians’ Journal Club，次年又发表在JAMA上。1993年，JAMA发表了名为医学文献使用者指南的系列文章。这些系列文章在2002年以同名书籍首次得以出版，同时还加上了副标题：循证医学手册。2008年出版了第二版，今年早些时候第三版也宣告问世。

作为McMaster大学著名的临床流行病学、生物统计学及内科学教授，同时也是上述书籍的主编，近期接受JAMA采访时谈到了最新出版的书籍。以下是经过编辑的谈话内容。

JAMA: 为什么现在需要对使用者指南进行更新？

Dr Guyatt: 距离前一版问世已历时6年，我们发表了很多新的使用者指南，以回答医学文献中当前存在及新出现的问题。我们希望把这些内容归纳成一部新书，还有部分章节的方法学有了很大改动或进展，我们也希望能够包括在新书中。

JAMA: 你能否介绍一下这些进展？

Dr Guyatt: 其中之一是非劣效研究。在传统的临床试验中，你发现了新的治疗方法，能够减少死亡或卒中或心脏事件，或能够改进生活质量。最近，新的治疗方法进入临床，并非因为这些治疗对上述主要预后指标显示良好的疗效，而是由于它们具有其他益处：减少副作用，使用更加方便，或减少负担。例如，新抗凝药物的问世并非因为能够减少卒中或其他血栓事件，而是由于使用这些抗凝药物可以避免华法令所特有的监测及药物相互作用问题。随着这些新的治疗方法的出现，新的临床试验设计也相继问世。我们的目的并非证实新的药物更好，而是新的药物并不太差。这就被称为非劣效研究，这一新的研究模式对解读及了解治疗提出了新的挑战。质量改进也是当前医学的重大问题。有关质量改进或质量保证、流程及程序的试验层出不穷。因此，书中有一个章节涉及质量改进研究的严格评估及应用。另一个新的领域是遗传相关研究，有很多研究验证某种特殊基因与不良预后或发生某种情况之间的相关性，例如与发生Alzheimer氏病相关的基因。新书中的一个章节讨论这些类型的研究。其他新的章节还介绍了别的进展：一个章节讨论了患者与医生共同进行决策，这越来越成为循证临床实践的重要部分。还有2个章节介绍系统回顾与meta分析。第一章介绍系统回顾与meta分析的区别，解释了系统回顾meta分析过程的可靠性。我们注意到，系统回顾是通过系统的可以重复的方法，对于解答同一临床问题的不同研究进行的总结。系统回顾可以伴随着meta分析，后者是对不同研究结果进行的统计学综合，能够对治疗、预后或诊断试验提供单一的最佳效果预测。第二张介绍了如何相信及应用系统回顾和meta分析的结果。这是新版书的主要改动，能够真正提升使用者指南的价值。

JAMA: 新版中还包括了网络meta分析的章节。这一部分为什么重要？

Dr Guyatt: 通常情况下，都是将某种特殊情况的治疗与安慰剂进行比较，或者将两种药物进行比较。但是，此时可能有6种甚至更多的药物可以使用。临床医生如何选择？在过去10年间，一种新的统计方法即网络meta分析(network meta-analysis)问世。这种方法可以同时比较A vs B vs C vs D vs E vs F，甚至更多。在新书中，我们介绍了网络meta分析的概念以及临床医生如何解读这些分析。很多很多网络meta分析在过去数年间得以发表。临床医生也会看看越来越多的文章，因此他们需要使用者指南。

JAMA: 你认为临床医生在找寻答案时会认为哪个章节最有帮助？

Dr Guyatt: 原有章节一个最重要的变化即有关证据的发现—查询最佳证据以回答你的问题。传统做法是让一个人去检索Medline以发现每一篇文章，但是我们现在建议大家首先利用高级医学文献、总结、实践指南及在线临床参考工具（如DynaMed, Clinical Evidence, InfoRetriever和PDxMD）查找未经处理的证据。我们提供了有关指导，介绍如何迅速高效地发现并解读未经处理的高质量证据。如果通过这些途径未能发现，你还是可以使用更加传统的资源如Medline检索。另一种工具革新了发现证据的方法，即发送相关领域令人激动的新消息的更新服务。很多类似服务是免费的，可以对你的领域定期进行更新。

JAMA: 奥巴马总统最近宣布了研究基因、健康及环境相互联系的新的精准医学计划。在这一计划中循证医学将发挥何种作用？

Dr Guyatt: 循证医学能够帮助人们谨慎看待研究结果。由于基因与预后相关并不意味着每个人都需要进行基因检测，也不意味着这一信息极有价值。在基因检测以及利用基因检测结果指导诊断和治疗方面存在很多令人兴奋的可能性。但同时也存在很多浪费资源甚至导致危害的可能。因此，精准医学与循证医学的关系在于，如果你了解循证医学的基本原则，你就能够鉴别能够改善预后的新的检查或诊断策略，以及那些仅仅消耗资源却没有任何益处甚至有害的检查。

JAMA: 你如何看待美国和其他国家的医学院有关循证医学的教学？

Dr Guyatt: 正在变得越来越好，但是仍然有很长的路要走。在过去4年间，我一直担任一个委员会的主席，负责将循证医学的考题加入美国医学执照考试。我们使用了一种新的方法。与询问知识问题不同，我们提供了与American College of Physicians’ Journal Club中相似的摘要—高质量未经处理的证据。然后，我们询问考生如何解读，以了解其掌握的情况。结果并非总是令人鼓舞，因此我们努力使考题简单直接。但是，根据目前得到的结果，我们还需要把考题变得更加简单更为直接。这告诉我们，在很多医学院，循证医学的概念并未深入人心，或相关教学并不正确。有时，考试能够推动课程改革，因此考试中暴露的问题可能促进美国医学院中有关循证医学的教学。

JAMA: 同样，你能否说说临床医生实施循证医学的情况如何？

Dr Guyatt: 仅有很少数研究真正告诉我们这一点，所以我的回答主要依据低质量的证据。即使如此，我认为年轻医生做的更好，他们至少接受过部分相关培训，而且更深切体会到其重要性。我们希望，即使临床医生不了解循证医学原则以及如何根据上述原则评估医学文献，他们仍然能够根据循证医学指南实施循证医疗实践。

JAMA: 循证医学曾被批评为“菜谱医学”。你是否仍然可以听到这样的批评？你如何回应呢？

Dr Guyatt: 我最喜欢的讲题之一就是循证医学实质上是以患者为中心的医学，因此，需要指出很多问题。可能最为重要的是证据本身从来不能告诉你要做什么，永远不会。解读证据必须结合价值观和喜好。换言之，一名持有某种价值观的患者可能说：“是的，这是正确的选择。”但是，另一名患者可能会说：“不。对于我而言，不良后果可能较预期获益更为重要。” 循证医学强调医疗决策经常需要考虑价值观和喜好。为向你的患者提供最佳治疗，你需要考虑其价值观和喜好，最好与患者共同参与决策。

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[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.

风吹麦浪-Jade

学习了，很好的资料！