Observational epidemiological studies provide an abundance of information on associations between biomarkers and disease outcomes. However, observational findings cannot be taken to indicate causal relationships between exposures and outcomes due to multiple complicating and intractable issues, e.g. residual and unmeasured confounding as well as reverse causality.^1,2

中文翻译：

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评论：理解危险因素的因果关系令人难以置信的障碍：前列腺癌。

观察流行病学研究提供了大量有关生物标志物与疾病结局之间关系的信息。但是，由于存在多种复杂而棘手的问题，例如残留和无法衡量的混杂以及反向因果关系，因此观察结果不能用来表明暴露与结果之间的因果关系。^{1 ，2}