Hayes Michael J, Kaestner Victoria, Mailankody Sham, Prasad Vinay
Affiliations: Division of Internal Medicine (Hayes); Division of Hematology and Medical Oncology (Kaestner, Prasad), Knight Cancer Institute, Oregon Health and Science University, Portland, Ore.; Division of Myeloma (Mailankody), Memorial Sloan Kettering Cancer Center, New York, NY; Department of Preventive Medicine and Public Health (Prasad); Center for Health Care Ethics (Prasad), Oregon Health and Science University, Portland, Ore.
CMAJ Open. 2018 Jan 15;6(1):E31-E38. doi: 10.9778/cmajo.20170088.
In a 2003 paper in , the authors made the tongue-in-cheek observation that there are no randomized controlled trials (RCTs) of parachutes. This paper has been widely read, cited and used to argue that RCTs are impractical or unnecessary for some medical practices. We performed a study to identify and evaluate claims that a medical practice is akin to a parachute.
Using Google Scholar, we identified all citations to the 2003 paper. We searched for claims that a specific practice was akin to a parachute. For each practice, we identified the desired outcome of the practice, and searched Google Scholar and ClinicalTrials.gov for RCTs that were conducted, ongoing, halted, planned or unpublished.
Of 822 articles citing the original paper, 35 (4.1%) argued that a medical practice was akin to a parachute. Eighteen of the 35 (51%) concerned mortality or live birth, and 17 (49%) concerned a lesser outcome. For 22 practices (63%), we identified 1 or more RCTs: in 6 cases (27%), the trials showed a statistically significant benefit of the practice; in 5 (23%), the trials rejected the practice; in 5 (23%), the trials had mixed results; in 2 (9%), the trials were halted; and in 4 (18%), the trials were ongoing. Effect size was calculated for 5 of the 6 practices for which RCTs gave positive results, and the absolute risk reduction ranged from 11% to 30.8%, corresponding to a number needed to treat of 3-9.
Although there is widespread interest regarding the paper arguing that randomized trials are not necessary for practices of clear benefit, there are few analogies in medicine. Most parachute analogies in medicine are inappropriate, incorrect or misused.
在2003年发表于某期刊的一篇论文中，作者半开玩笑地指出，目前尚无关于降落伞的随机对照试验（RCT）。这篇论文被广泛阅读、引用，并被用于论证RCT对于某些医疗实践而言不切实际或并无必要。我们开展了一项研究，以识别和评估那些认为某种医疗实践类似于降落伞的观点。
利用谷歌学术，我们找出了所有引用2003年那篇论文的文献。我们搜索了认为某种特定实践类似于降落伞的观点。对于每种实践，我们确定该实践期望达成的结果，并在谷歌学术和ClinicalTrials.gov上搜索已开展、正在进行、已停止、已计划或未发表的RCT。
在822篇引用原文的文章中，有35篇（4.1%）认为某种医疗实践类似于降落伞。这35篇文章中有18篇（51%）涉及死亡率或活产，17篇（49%）涉及次要结局。对于22种实践（63%），我们找到了1项或更多RCT：其中6例（27%）试验显示该实践具有统计学显著益处；5例（23%）试验否定了该实践；5例（23%）试验结果不一；2例（9%）试验已停止；4例（18%）试验正在进行。对于RCT给出阳性结果的6种实践中的5种，计算了效应量，绝对风险降低范围为11%至30.8%，相应的需治疗人数为3至9。
尽管对于那篇认为随机试验对于明显有益的实践并非必要的论文存在广泛关注，但医学领域中此类类比甚少。医学中大多数降落伞类比都不恰当、不正确或被滥用。
