Establishment of Ascertainment Methods for Cardiovascular Disease Onset in the Tohoku Medical Megabank Organization.

Background: In order to collect information on the onset of cardiovascular disease (CVD) events for participants, the Tohoku Medical Megabank Organization (ToMMo) constructed a system to identify CVD events using a self-administered questionnaire regarding CVD onset. The association between traditional cardiovascular risk factors and CVD onset was also examined. Methods and Results: This study included participants from the ToMMo's Community-based Cohort Study and the Birth and Three-Generation Cohort Study. To identify CVD onset, the participants were first asked about stroke, myocardial infarction, and angina pectoris using self-administered questionnaires. Next, for those reporting onset, the ToMMo mailed structured CVD registration forms to their medical institutions. These institutions used medical records to complete and return the forms. CVD onset was then determined at event adjudication meetings involving multiple physicians and epidemiologists, based on the information from these registration forms. A nested case-control study with 602 CVD cases and 1,204 matched controls using data from a Community-based Cohort Study of the ToMMo was conducted. Using conditional logistic regression models, we found significant association between traditional CVD risk factors, such as hypertension and dyslipidemia, and CVD onset. Conclusions: The ToMMo establishes a system for identifying CVD onset in cohort study participants. In the future, combining participants' lifestyles and genomic information with CVD onset may help build evidence for personalized prevention and medicine.