Individual income, income distribution, and self rated health in Japan: cross sectional analysis of nationally representative sample.
OBJECTIVE
To assess the effects on self rated health of individual income and income distribution in Japan.


METHODS
Cross sectional analysis. Data collected on household income, self rated health, and other sociodemographic characteristics at the individual level from comprehensive survey of the living conditions of people on health and welfare in a nationally representative sample from each prefecture.


METHODS
Prefectures in Japan.


METHODS
80 899 people aged >15 years with full records in survey.


METHODS
Dichotomous variable for self rated health of each respondent (0 if excellent, very good or good; 1 if fair or poor).


RESULTS
Inequality in income at the prefecture level measured by the Gini coefficient was comparable with that in other industrialised countries. Unadjusted odds ratios show a 14% increased risk (odds ratio 1.14, 95% confidence interval 1.02 to 1.27) in reporting poor or fair health for individuals living in prefectures with higher inequality in income. After adjustment, individual income was more strongly associated with self rated health than income inequality. Additional inclusion of regional effects showed that median income at the prefecture level was inversely related to self rated health.


CONCLUSIONS
Individual income, probably relative to the median prefecture income, has a stronger association with self rated health than income inequality at the prefecture level.
Shibuya
Kenji
K
Department of Hygiene and Public Health, Teikyo University School of Medicine, Tokyo, Japan.
Hashimoto
Hideki
H
Yano
Eiji
E
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D003430:Cross-Sectional Studies; D005260:Female; D006304:Health Status; D006801:Humans; D007182:Income / Q000706:statistics & numerical data*; D007564:Japan; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011203:Poverty / Q000706:statistics & numerical data*; D012307:Risk Factors