抄録
Regional differences of health levels in Japan have been decreasing since World War II due to the rapid economical growth. Since health phenomena are related to socio-economic factors, the decreasing trend of the regional differences of health levels are being considered. In this study, the infant mortality rate, age-adjusted death rate, and life expectancy (at age 0 year) were observed as health indexes, in order to investigate the trends of the above mentioned regional differences, using data obtained from health statistics in Japan. Coefficient of variation (C.V.) was employed to measure the regional differences. Since the test statistics for C.V. will be normally distributed, criticl significance level for null hypothesis test was calculated as an exact probability based on the Hastings' approximation. From the results, the coefficient of variation for the infant mortality rate was 17.93% as in 1950, and in 1984, this coefficient became 10.96% (critical significance level P=0.0024). The age-adjusted death rate for males in 1960 was 7.40%, and 6.02% for females. In 1980, the values decreased until 5.87% (critical significan e level P=0.0616) and 5.07% (critical significance level P=0.1241) respectively. The life expectancy in 1950 was 2.70% for males and 3.28% for females, and in 1980 0.94% and 0.75% respectively. Very small values of significance level were observed. Therefore, it can be concluded that the regional differences of health level in Japan have been decreasing significantly.
