(一)什么是混杂因素?研究疾病与暴露的相互关系时,往往受无关变量的影响所混淆而出现偏倚,这个无关变量叫混杂因素。作为混杂因素的条件:一方面它是所研究疾病的一种病因或是与该病病因密切相关的变量因素(例如年龄、性别等);另一方面它又与所研究的暴露因素有关。 (A) What is a confounding factor? When studying the relationship between disease and exposure, it is often confused by the influence of unrelated variables to appear bias. This irrelevant variable is called a confounding factor. As a confounding condition: on the one hand it is a cause of the disease being studied or a variable factor closely related to the etiology of the disease (eg age, gender, etc.); on the other hand it is related to the exposure factors studied.