A Tutorial on Methods to Estimating Clinically and Policy-Meaningful Measures of Treatment Effects in Prospective Observational Studies: A Review
A Tutorial on Methods to Estimating Clinically and Policy-Meaningful Measures of Treatment Effects in Prospective Observational Studies: A Review
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DOI：
10.2202/1557-4679.1285
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发表时间：
2011-01-01
影响因子：
1.2
通讯作者：
Laupacis, Andreas
中科院分区：
文献类型：
--
作者：
Austin, Peter C.;Laupacis, Andreas
在随机对照试验（RCTs）中，治疗分配与基线协变量不相混淆，允许在治疗组之间直接比较结果。当结果是二元的，治疗效果可以用相对危险度、绝对危险度降低和需要治疗的次数（NNT）来总结。当结果本质上是时间到事件时，可以估计在特定随访时间内治疗对事件发生风险绝对降低的影响以及相关的NNT。在治疗对健康结果影响的观察性研究中，治疗经常与基线协变量混淆。回归调整通常用于估计治疗对结果的调整效果。我们强调了直接从回归模型中获得的治疗效果测量的几个局限性。我们说明了基于回归的方法和基于倾向评分的方法如何允许人们估计与随机对照试验中通常报道的治疗效果相同的测量值。CONSORT声明建议，对于具有二分类结果的随机对照试验，报告治疗效果的相对和绝对指标。本文中描述的方法将允许在观察性研究中进行类似的报告。
In randomized controlled trials (RCTs), treatment assignment is unconfounded with baseline covariates, allowing outcomes to be directly compared between treatment arms. When outcomes are binary, the effect of treatment can be summarized using relative risks, absolute risk reductions and the number needed to treat (NNT). When outcomes are time-to-event in nature, the effect of treatment on the absolute reduction of the risk of an event occurring within a specified duration of follow-up and the associated NNT can be estimated. In observational studies of the effect of treatments on health outcomes, treatment is frequently confounded with baseline covariates. Regression adjustment is commonly used to estimate the adjusted effect of treatment on outcomes. We highlight several limitations of measures of treatment effect that are directly obtained from regression models. We illustrate how both regression-based approaches and propensity-score based approaches allow one to estimate the same measures of treatment effect as those that are commonly reported in RCTs. The CONSORT statement recommends that both relative and absolute measures of treatment effects be reported for RCTs with dichotomous outcomes. The methods described in this paper will allow for similar reporting in observational studies.