生物与医学2012bmj.com编辑精选
降落伞用于预防重力挑战所致死亡和严重创伤
Parachute use to prevent death and major trauma due to gravitational challenge
入门 · 约 15 分钟读完前置知识：随机对照试验概念、循证医学基础
导读
这是 BMJ 2003 年圣诞特刊上的经典讽刺论文：作者用系统综述的口吻指出，降落伞预防高空坠落死亡这一'干预措施'从未经过随机对照试验验证，以此调侃循证医学对 RCT 的过度崇拜。文中一本正经地呼吁对降落伞开展随机试验，实为医学幽默。
HN 关注点：是因为它触及'循证医学 vs 基于科学的医学'之争：RCT 是否是评估疗效的唯一标准，还是应结合先验概率和基础科学原理。
后来怎么样
成为循证医学讨论中被广泛引用的经典讽刺范例，'降落伞类比'由此成为医学界争论证据等级时的标志性梗，并引出多篇后续评论与研究。
HN 评论精选
这几条评论里：支持 1 质疑 1 补充 2
补充主张用'基于科学的医学'补充循证医学，重视先验概率
临床试验应当考虑先验概率。这也是一些医学研究者推崇'基于科学的医学'而非'循证医学'的原因：EBM 往往过度强调临床试验证据的价值，导致纳税人的钱花在价值可疑的'更多研究'上；SBM 并非与 EBM 对立，而是主张综合各学科的累积科学知识来回答'什么有效'。
tokenadult查看英文原文
Some of the comments made by HN participants who posted during the first hour this 2003 article was posted bring up the main point: clinical trials should be informed by prior probabilities. That's why some medical researchers, while not saying that clinical trials are a bad idea, identify the best practice as "science-based medicine" (medicine that takes into account prior probabilities and basic principles of science when evaluating clinical trials) rather than "evidence-based medicine" (which many observers take to be a designation for relying on clinical trials to evaluate treatments). The "About" page on the Science-Based Medicine group blog site puts it well: http://www.sciencebasedmedicine.org/index.php/about-science-based-medicine/ "Good science is the best and only way to determine which treatments and products are truly safe and effective. That idea is already formalized in a movement known as evidence-based medicine (EBM). EBM is a vital and positive influence on the practice of medicine, but it has limitations and problems in practice: it often overemphasizes the value of evidence from clinical trials alone, with some unintended consequences, such as taxpayer dollars spent on 'more research' of questionable value. The idea of SBM is not to compete with EBM, but a call to enhance it with a broader view: to answer the question 'what works?' we must give more importance to our cumulative scientific knowledge from all relevant disciplines." The previous comments posted here mentioning what we can know about falling human bodies from first principles of how free fall in the earth's near gravitational field works, or by experiments with dummies including instruments, or by historical experience with aircraft disasters, correctly point out that randomized controlled trials should be designed with all the relevant science in mind. Further, clinical trials should be designed both to gain knowledge of the effectiveness of varying treatments and to minimize risk to human subjects of treatments (jumping out of an airplane without a parachute, for example, or using acupuncture, for another example) with no strong evidence of effectiveness. See my all-time favorite link to share in HN comments, LISP hacker and rocket scientist (and now director of research at Google) Peter Norvig's article "Warning Signs in Experimental Design and Interpretation" http://norvig.com/experiment-design.html on how to interpret scientific research. AFTER EDIT: In answer to the question, "Where is the evidence that EBM or SBM helps?", the evidence is all around you, all over the world. I've lived in more than one country, and I have had access to the research library of a major university health sciences center since I was in high school, and the incremental improvements in human lifespan at all ages, young and old, and the reduction in disease burden from all kinds of diseases http://www.scientificamerican.com/article.cfm?id=longevity-why-we-die-global-life-expectancy are an outcome caused in large part by better understanding of how to prevent or treat disease, an understanding that comes about from science-based medicine. The article I just submitted today http://news.ycombinator.com/item?id=4644708 about systematic reviews of acupuncture research in China illustrates the drawbacks of doing anything but science-based research on human disease prevention and treatment. People can imagine that a lot of speculative treatments work, but the way to demonstrate that one treatment or another works is to investigate it carefully with the underlying science in mind.
支持定性为医学幽默兼对循证医学的批评
最好把它理解为医学幽默与对循证医学批评的结合：指出降落伞从未有过对照随机试验，以此质疑这种评估方式对'救命干预'疗效评价的影响。
cstross查看英文原文
Best understood in context as a combination of medical humour, and a critique of evidence-based medicine. In this case pointing out the lack of controlled randomized trials of parachutes, and how this would affect the evaluation of the efficacy of parachutes as a life-saving medical intervention.
质疑反驳作者：降落伞确实经过测试，循证医学是必要的
这让我有点恼火：降落伞当然被测试过，飞机乘员逃生系统投入了大量研发。作者只是在抱怨循证医学——而循证医学正是因为人们意识到许多医疗干预基于直觉、道听途说或糟糕的小试验才被推动的。人类极擅长看出不存在的模式，我们需要扎实的统计来立足现实。
Zarkonnen查看英文原文
This is kind of making me froth: of course parachutes are tested. Lots and lots of R&D time has gone into developing better crew/passenger escape system for aircraft. The authors are simply whining about evidence-based medicine, which is now finally being pushed after a realisation that a lot of the medical interventions we use are based on gut feeling, hearsay, or ancient, tiny, badly-implemented trials. Human beings are extremely good at seeing patterns where there are none. We need good, solid stats to keep us grounded in reality.
补充指出降落伞类比常被滥用来为无效干预辩护
虽然听起来像玩笑，但有证据表明'降落伞类比'被严重滥用（附 PubMed 链接）。这个类比的逻辑是某些干预显而易见、无需严格证据，但人们常用它来为后来被证明无效的干预辩护。
hannob查看英文原文
This may sound like fun, but there's some evidence that the parachute analogy has been massively overused: https://pubmed.ncbi.nlm.nih.gov/29343497/ Like the idea here is that there are some interventions that are so obvious that you don't need rigorous evidence to show they work. However as it turns out people use that analogy to justify interventions that did later turn out to not work.
相关资源
从这篇论文所有 HN 讨论帖的全部评论里整理出来的链接。
历次讨论
- 2012Hacker News 讨论帖110 分 · 57 评
- 2021Hacker News 讨论帖78 分 · 30 评
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