Using foreign clinical trial data in new drug submission, new drug can be approved with a few observations of Japanese patients. In current Japanese drug development situation, the importance of post-marketing surveillance (PMS) for Japanese patients has been increased. Rigid PMS system in Japan which has no selective options should be rescinded. In order to perform primary role of PMS which is to keep in safety and efficacy of pharmaceutical and medical devices, the Japanese PMS should change from standard form to selection of study design according to scientific consideration. The paper proposed that new pharmaco-epidemiology research design was applied to PMS and PMS were conducted by independent and integrated data center based disease registry.

In this article, we provide a brief summary of study design of case-control study within a cohort and an introduction of two case-control studies within a cohort conducted in Japan recently using antihypertensive drug database based on the post-marketing surveillance data of pharmaceutical companies. In the case-control study within a cohort, it is possible to avoid bias caused in a case-control study and conduct more efficiently than cohort study. Therefore the case-control study within a cohort widely has been used in pharmacoepidemiological studies with a database. (Jpn J Pharmacoepidemiol 2013; 18(2): 77-83)

In this article, we provide a brief summary of a case-cohort study design and an introduction of Japan Statin Study (JSS) as an example for case-cohort study conducted in Japan. In the case-cohort study, the control as a sub-cohort is randomly selected from a research cohort at the beginning of the study. As it is not necessary to be sampled a control by interesting event in the research, the study design as well as cohort study can examine some events in the same time. Therefore the study design can be also applied to pharmaco-vigilance survey. The case-cohort study design has wide application range. (Jpn J Pharmacoepidemiol 2013; 18(2): 84-89)

Case-crossover study is research using only data from cases, patient with interested event. Getting control from own data, the case-crossover study is classified into self-controlled study. It has a lot of condition to be valid study. When study satisfies the conditions, the case-crossover has a lot of advantage in which it is not necessary to collect information of control group patients, and the control is to be matched genetic and other background. The paper is summarized the case-crossover study design. (Jpn J Pharmacoepidemiol 2013; 18(2): 90-94)

In pharmacoepidemiology, cohort studies and case-control studies have been commonly used as research methods to examine causal relationship between exposures to medicines and occurrences of advance events. For both study designs, we could assume a common population at risk, in which cases are developed. A cohort study defines a research cohort within the population at risk and tries to investigate the research cohort directly, and a case-control study tries to investigate the research cohort partly by the control sampling. Assuming an underling research cohort, it becomes possible to understand cohort studies and case-control studies within an unified framework. We revisited several sampling methods to select controls in case-control studies and effect measures implied by the sampling methods. (Jpn J Pharmacoepidemiol 2013; 18(2): 95-111)