When performing epidemiological studies to evaluate one or more determinants for a specific outcome, the other determinants may act as confounding factors, and need to be controlled for, e.g. by stratification.
当进行流行病学研究以评估特定结果的一个或多个决定因素时，其他决定因素可以作为混杂因素，并且需要例如通过分层来控制。