History and Outline
Funded by the Japan Arteriosclerosis Prevention Fund (JAPF), the Japan Arteriosclerosis Longitudinal Study (JALS) statistically integrates anonymous personal data collected in cardiovascular cohort studies in Japan and quantitatively evaluate cardiovascular disease risks and risk factors in the Japanese. The JALS activities include prospective integration of cohort study data using standardized investigational methods (integrated study) and integration of individual data from past Japanese cohort studies using loosely standardized methods (primordial integrated study). Participating researchers who provide data from their regional cohort studies receive research funds for their own as well as financial support from the JAPF based on annual application and review. The JALS administration office established in a non-profit organization Japan Clinical Research Supporting Unit (J-CRSU) collects and analyzes data from the integrated studies.
The JALS was started with a meeting for standardization of investigational methods in August 2001. The methods of blood pressure measurement, blood testing, and interview to identify background factors used in the existing cardiovascular epidemiological studies were standardized, and use of uniform diet and physical activity survey forms was encouraged since lifestyle surveys would be crucial in future epidemiological studies. After the meeting, briefing sessions were held for interested researchers to recruit participating institutions. A working group was formed to develop and validate diet and physical activity survey forms.
A baseline survey for an integrated study was conducted from 2002 to December 2004 (or to March 2005 in some cohorts), and 34 regional cohorts (about 70 municipalities and 9 occupational fields) were integrated into a single cohort of about 120,000 people. A database for the baseline survey is being created by the JALS administration office. Publication of the database is expected in a short time.
For follow-ups and case registration after the baseline survey, review committee meetings and workshops have been held to form a consensus on method standardization among researchers. Details of case registration method are summarized in “Case Registration Handbook” to standardize the method among cohorts as in the baseline survey and ensure follow-ups at certain accuracy.