Glesby M J, Hoover D R
Department of Epidemiology, Johns Hopkins University School of Hygiene and Public Health, Baltimore, MD 21205, USA.
Ann Intern Med. 1996 Jun 1;124(11):999-1005. doi: 10.7326/0003-4819-124-11-199606010-00008.
Unlike patients in a randomized, clinical trial, patients in an observational study choose if and when to begin treatment. Patients who live longer have more opportunities to select treatment; those who die earlier may be untreated by default. These facts are the essence of an often overlooked bias, termed "survivor treatment selection bias," which can erroneously lead to the conclusion that an ineffective treatment prolongs survival. Unfortunately, misanalysis of survivor treatment selection bias has been prevalent in the recent literature on the acquired immunodeficiency syndrome. Approaches to mitigating this bias involve complex statistical models. At a minimum, initiation of therapy should be treated as a time-dependent covariate in a proportional hazards model. Investigators and readers should be on the alert for survivor treatment selection bias and should be cautious when interpreting the results of observational treatment studies.
与随机临床试验中的患者不同，观察性研究中的患者自行选择是否开始治疗以及何时开始治疗。存活时间较长的患者有更多机会选择治疗；而那些较早死亡的患者可能默认未接受治疗。这些事实是一种常被忽视的偏差的核心，这种偏差被称为“幸存者治疗选择偏差”，它可能错误地导致这样的结论：一种无效的治疗方法能延长生存期。不幸的是，在最近关于获得性免疫缺陷综合征的文献中，对幸存者治疗选择偏差的错误分析很普遍。减轻这种偏差的方法涉及复杂的统计模型。至少，在比例风险模型中，治疗的开始应被视为一个随时间变化的协变量。研究者和读者应警惕幸存者治疗选择偏差，在解释观察性治疗研究的结果时应谨慎。
