The aim of the JALS

In the rapidly aging society, prevention of arteriosclerotic disease is increasingly important in Japan. Hypertension, hyperlipidemia, diabetes, smoking, obesity, and various other factors are involved in arteriosclerotic disease. The Japan Arteriosclerosis Longitudinal Study (JALS) is an integrated research project initiated in cooperation with the Japan Arteriosclerosis Prevention Fund to identify factors causing arteriosclerotic disease affecting the Japanese based on large-scale cohort studies.

A number of excellent cohort studies have been conducted in Japan. However, these studies are relatively small-scale and specific to limited regions. The JALS integrates personal data from the cohort studies conducted by independent researchers and performs metanalyses to initiate a representative cohort study.

Trust and a consensus-building among those involved are most important in joint research. A 2-day workshop was held in the beginning to deepen the understanding of joint research and form consensus among researchers. About 50 researchers were divided into 8 groups to discuss why joint research based on large-scale individual metanalyses is needed in Japan, what the study objective and endpoints should be, and how to standardize investigational methods. Based on the outcome of workshops, consensus building was further promoted by establishing the JALS committee and developing an Internet forum where free discussions are guaranteed. Several briefing sessions were held to answer the questions of researchers. Study groups were formed to discuss and decide on the method of blood pressure measurement, uniform interview forms, nutritional survey method, and exercise and physical activity evaluation, and the decisions were reflected on the study activities.

There are 2 types of integrated study. One is prospective integration of cohort study data using standardized methods (integrated study), and the other is integration of individual data from past Japanese cohort studies followed by loose standardization of investigational methods (primordial integrated study). An integrated study will follow some 100,000 people for 5 to 10 years while a primordial integrated study evaluates data from past cohort studies using uniform analysis items that are integrated in loosely standardized methods.

Success of integrated study depends on how much important issues such as guarantee of benefits to participating researchers, significance of the study, how to conduct the study, and feasibility of the study, are resolved. With the tireless support from the JALS administration office, consensus building has been surely promoted to make the integrated study project possible through workshops, briefing sessions, study groups, and integrated communication. We hope the teamwork of participating researchers will be further strengthened.

Hirotsugu Ueshima
Hirotsugu Ueshima 
Chairman, the Japan Arteriosclerosis Longitudinal Study (JALS)