From the Department of Epidemiology, University of North Carolina at Chapel Hill, Chapel Hill, NC.
Epidemiology. 2018 May;29(3):352-355. doi: 10.1097/EDE.0000000000000813.
Since being introduced to epidemiology in 2000, marginal structural models have become a commonly used method for causal inference in a wide range of epidemiologic settings. In this brief report, we aim to explore three subtleties of marginal structural models. First, we distinguish marginal structural models from the inverse probability weighting estimator, and we emphasize that marginal structural models are not only for longitudinal exposures. Second, we explore the meaning of the word "marginal" in "marginal structural model." Finally, we show that the specification of a marginal structural model can have important implications for the interpretation of its parameters. Each of these concepts have important implications for the use and understanding of marginal structural models, and thus providing detailed explanations of them may lead to better practices for the field of epidemiology.
自 2000 年引入流行病学以来，边缘结构模型已成为广泛的流行病学环境中因果推断的常用方法。在这份简要报告中，我们旨在探讨边缘结构模型的三个细微差别。首先，我们将边缘结构模型与逆概率加权估计器区分开来，并强调边缘结构模型不仅适用于纵向暴露。其次，我们探讨了“边缘结构模型”中“边缘”一词的含义。最后，我们表明边缘结构模型的规范对其参数的解释有重要影响。这些概念中的每一个都对边缘结构模型的使用和理解有重要影响，因此详细解释它们可能会为流行病学领域带来更好的实践。
