Department of Epidemiology, Fielding School of Public Health, University of California, Los Angeles, CA, USA.
Department of Statistics, College of Letters and Science, University of California, Los Angeles, CA, USA.
Eur J Epidemiol. 2018 May;33(5):503-506. doi: 10.1007/s10654-018-0395-7.
We thank Dr. Karp for his interest [1] in our paper [2]. We agree on some points, but our theoretical description differs from his in ways leading to important divergences for teaching and practice. We also see a danger of overextending abstract theory (with its inevitable and extensive simplifications) into practice [3], especially when the practical questions are causal but the theory applied lacks an explicit, sound longitudinal causal model to address these questions. As we will explain, a defect in the “study base” theory Dr. Karp adopts as a foundational belief system is that it takes as a foundation a parameter affected by baseline risk factors—including exposure when that has effects on follow-up or disease. It consequently leads to biases and misconceptions of the sort documented elsewhere [4, 5] and below, which require a coherent theory of longitudinal causality to address. Our divergence from Dr. Karp thus raises the issue of the role of theory and methods in research, although matching serves to illustrate our points in a familiar epidemiologic context.
我们感谢 Karp 博士对我们论文的关注。我们在一些观点上达成了一致，但我们的理论描述与他的理论描述存在差异，这些差异对教学和实践产生了重要的分歧。我们还看到了将抽象理论（不可避免地进行了广泛简化）过度应用于实践的危险，尤其是当实际问题是因果关系，但所应用的理论缺乏明确、合理的纵向因果模型来解决这些问题时。正如我们将解释的那样，Karp 博士采用的作为基础信仰体系的“研究基础”理论的一个缺陷是，它将一个受到基线风险因素影响的参数作为基础，其中包括当暴露对随访或疾病有影响时的暴露。因此，它导致了其他地方记录的和下面将要讨论的那种偏见和误解，需要一个连贯的纵向因果关系理论来解决这些问题。因此，我们与 Karp 博士的分歧提出了理论和方法在研究中的作用问题，尽管匹配有助于在熟悉的流行病学背景下说明我们的观点。
