The curse of the perinatal epidemiologist: inferring causation amidst selection.
The curse of the perinatal epidemiologist: inferring causation amidst selection.
复制标题
围产期流行病学家的诅咒:在选择中推断因果关系。
DOI:
10.1007/s40471-018-0172-x
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发表时间:
2018
影响因子:
3.3
通讯作者:
Basso,Olga
中科院分区:
文献类型:
--
作者:
Snowden,JonathanM;Bovbjerg,MaritL;Dissanayake,Mekhala;Basso,Olga
Purpose of ReviewHuman reproduction is a common process and one that unfolds over a relatively short time, but pregnancy and birth processes are challenging to study. Selection occurs at every step of this process (e.g., infertility, early pregnancy loss, and stillbirth), adding substantial bias to estimated exposure-outcome associations. Here, we focus on selection in perinatal epidemiology, specifically, how it affects research question formulation, feasible study designs, and interpretation of results.Recent FindingsApproaches have recently been proposed to address selection issues in perinatal epidemiology. One such approach is the ongoing pregnancies denominator for gestation-stratified analyses of infant outcomes. Similarly, bias resulting from left truncation has recently been termed “live birth bias,” and a proposed solution is to control for common causes of selection variables (e.g., fecundity, fetal loss) and birth outcomes. However, these approaches have theoretical shortcomings, conflicting with the foundational epidemiologic concept of populations at risk for a given outcome.SummaryWe engage with epidemiologic theory and employ thought experiments to demonstrate the problems of using denominators that include units not “at risk” of the outcome. Fundamental (and commonsense) concerns of outcome definition and analysis (e.g., ensuring that all study participants are at risk for the outcome) should take precedence in formulating questions and analysis approaches, as should choosing questions that stakeholders care about. Selection and resulting biases in human reproductive processes complicate estimation of unbiased causal exposure-outcome associations, but we should not focus solely (or even mostly) on minimizing such biases.