Health and its determining factors in the Tokyo megacity.
This study was designed to (i) analyze community health in post-industrial, densely populated Tokyo, and (ii) find a statistical-based prediction model for the health level of the communities from the environment. For this purpose, we compiled health-level indicators for each city-ward, and indicators for demography, infrastructure, land-use, amenities, education, working conditions, economics, and medical and welfare services. The health factors and the environmental factors were obtained by using weighted principal factor analysis; their relation was examined by weighted correlation analysis and weighted linear regression analysis. One to six environmental factors correlating significantly to health were found for each health-level indicator or factor. The prediction model explained up to 0.98 of the variance of the health-level factors and indicators. This analysis elicited health-determinant factors in various fields. The community health level was well reproduced by the present method; the model will be conducive to decision making pertaining to health policies.