The case-referent (case-control) study in occupational health epidemiology.

Abstract

The case-referent (case-control) method represents a convenient alternative to the cohort design, which is used for morbidity and mortality in an industrial population. The primary information from a case referent study is the difference in exposure frequency between the cases of the disease and the referent. Given a reasonably common exposure, a case-referent study requires less extensive data acquisition than the cohort approach. From the case-referent study, only relative measures of effect, i.e., risk or rate ratio, can be directly obtained. The problems of the case-referent study include selection of subjects, exposure information, reference entity and confounding. A study of As as a possible cause of various disorders, e.g., lung cancer or cardiovascular disease, is used as an example for the case-referent method.