Case-control Design and Real-world Database Studies / 薬剤疫学

ABSTRACT

A case-control design is one of common study designs in epidemiology. A case with an outcome event of interest is identified and a corresponding control without an outcome event is sampled from a study base, which give rise to the cases. Distribution of a past exposure to an agent of interest before the timing of sampling is compared between a case group and a control group, to yield an odds ratio of exposure as a risk index. A cohort design is usually costly because it requires a large sample size and a long-term follow-up period to power a study especially to detect rare outcome events. In contrast, a traditional case-control design brings efficiency in resource and time to study the association of an exposure and an outcome event by reducing a sample size to study an exposure and covariates after sampling compared with a traditional cohort design. This review article discusses whether a case-control sampling strategy in healthcare database studies, where all the data for the study variables necessary for analysis already exist and are readily available, remains advantageous over a cohort design from the viewpoints of study cost and utility.