It is emphasised that for epidemiological studies where disease incidence is rare, results from conventional proportional hazards models can often correctly estimate causal associations. The well-known "backdoor criteria" from causal-inference is applied to the common epidemiological study of rare diseases with a proportional hazards model, providing an example of when and how estimates from conventional proportional hazards studies can be used. A similar study with the "frontdoor criteria", that allows studies with unmeasured confounders, finds similar results to conventional mediation analysis with measured confounders. Reasons for this are discussed.

翻译：人们强调,对于罕见的疾病发病率的流行病学研究,传统比例危害模型的结果往往可以正确地估计因果关系。由因果推断得出的众所周知的“后门标准”适用于具有比例危害模型的稀有疾病的常见流行病学研究,为何时以及如何使用常规比例危害研究的估计数提供了一个实例。 与“前门标准”类似的研究,允许与非计量的混杂者进行研究,其结果与与与有计量的混杂者进行的传统调解分析相似。