Socioeconomic inequalities in oral health among unmarried and married women: Evidence from a population-based study in Japan

Background: Socioeconomic inequalities in oral health have been reported in developed countries, but the influence of marital status has rarely been considered. Our aim was to examine marital status differentials in the association between socioeconomic status (SES) and oral health among community-dwelling Japanese women. Methods: From 2010 to 2011, a questionnaire survey was conducted among residents aged 25–50 years in Japanese metropolitan areas. Valid responses were received from 626 unmarried women and 1,620 married women. Women’s own and husbands’ educational attainment and equivalent income were used to assess SES. Self-rated “fair” or “poor” oral health was defined as poor oral health. Multiple logistic regression analysis was conducted to examine which SES indicators were associated with oral health. Results: The prevalence of poor oral health was 21.1% among unmarried women and 23.8% among married women. Among unmarried women, equivalent income was not associated with oral health, but women’s own education was significantly associated with oral health; the multivariate-adjusted odds ratio of poor oral health among those with high school education or lower compared to those with university education or higher was 2.14 (95% confidence interval, 1.19–3.87). Among married women, neither women’s own nor husbands’ education was associated with oral health, but equivalent income was significantly associated with oral health, particularly among housewives; the multivariate-adjusted odds ratio of poor oral health among those in the lowest compared with highest income quartile was 1.57 (95% confidence interval, 1.08–2.27). Conclusions: These findings indicate that marital status should be considered when examining associations between SES and oral health among Japanese women.