arXivDaily arXiv每日学术速递 周一至周五更新
arXiv周末暂无论文更新,休息一下吧,周末愉快~~
arXiv 2302.00840stat.ME
收藏

流行病学因果推断中的通用双重差分法

Universal Difference-in-Differences for Causal Inference in Epidemiology

Eric Tchetgen Tchetgen, Chan Park, David Richardson

AI总结:

针对传统双重差分法依赖平行趋势假设、难以适用于非线性结局的问题,提出基于比值比等混杂假设的 UDiD,可识别多种非线性因果效应,并给出参数与半参数估计量。

摘要:

双重差分法无疑是观察性(即非随机化)环境中评估干预措施因果效应最广泛使用的方法之一。该方法通常用于可获得暴露前和暴露后结局测量的情形,并且人们可以合理假设未观测混杂因素与结局的关联在两个暴露组中具有相同的绝对量级,且随时间保持恒定;这就是所谓的平行趋势假设。在许多实际场景中,平行趋势假设可能并不可信,包括当结局为二分类、计数或多分类时,以及当未控制混杂因素对结局分布表现出非加性效应时,即使此类效应随时间保持恒定。我们引入一种替代方法,用比值比等混杂假设取代平行趋势假设;在该假设下,处理与无处理情形下潜在结局之间的关联,可通过一个将暴露前结局与暴露相联系且设定良好的广义线性模型加以识别。由于所提出的方法能够识别在不存在混杂偏倚的情况下可设想被识别的任何因果效应,包括分位数处理效应等非线性效应,因此该方法被恰当地称为通用双重差分法(Universal Difference-in-differences,UDiD)。文中描述了完全参数化和更稳健的半参数化 UDiD 估计量,并通过一个关于巴西寨卡病毒暴发对出生率因果效应的真实应用进行了说明。

英文摘要:

Difference-in-differences is undoubtedly one of the most widely used methods for evaluating the causal effect of an intervention in observational (i.e., nonrandomized) settings. The approach is typically used when pre- and post-exposure outcome measurements are available, and one can reasonably assume that the association of the unobserved confounder with the outcome has the same absolute magnitude in the two exposure arms, and is constant over time; a so-called parallel trends assumption. The parallel trends assumption may not be credible in many practical settings, including if the outcome is binary, a count, or polytomous, as well as when an uncontrolled confounder exhibits non-additive effects on the distribution of the outcome, even if such effects are constant over time. We introduce an alternative approach that replaces the parallel trends assumption with an odds ratio equi-confounding assumption under which an association between treatment and the potential outcome under no-treatment is identified with a well-specified generalized linear model relating the pre-exposure outcome and the exposure. Because the proposed method identifies any causal effect that is conceivably identified in the absence of confounding bias, including nonlinear effects such as quantile treatment effects, the approach is aptly called Universal Difference-in-differences (UDiD). Both fully parametric and more robust semiparametric UDiD estimators are described and illustrated in a real-world application concerning the causal effects of a Zika virus outbreak on birth rate in Brazil.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑