Longitudinal studies on the relationship of life-style factors and social networking with mortality have been only slightly conducted in a comprehensive manner among the Japanese elderly. This study aims at examining associations of health behavior and social role with total mortality among Japanese elders in Okinawa.
All residents aged 65 years or older were recruited in 1987 from the village of Ohgimi, and 724 subjects were followed for 12 years. A comprehensive health assessment questionnaire was used, and the resulting data were analyzed by the Cox proportional hazards model.
The number of deaths during the study period was 139 (55.4%) for men and 166 (35.1%) for women. The standardized mortality rates of malignancy, cerebrovascular disease, heart disease and pneumonia were higher for men. In the final model of multivariate analysis for women, less than 6 hours of sleep [Hazard ratio (HR)=2.62] and lower social role (HR=1.88) significantly increased the risk of mortality. As for men, neither health behavioral items nor social role showed a significant association with mortality.
Our study results suggest that having sufficient hours of sleep and enhancing social role could greatly help elderly women in Okinawa to maintain good health. Moreover, our study provides direction for future research to explore the difference in adequate health promotion measures between women and men.