Education‐related inequalities in oral health among older adults: Comparing Singapore and Japan

Abstract Objectives Oral health inequalities exist worldwide, and cross‐country comparisons can provide valuable insights into country‐level characteristics contributing to such inequalities. However, comparative studies in Asian countries are limited. This study examined the magnitude of education‐related oral health inequalities in older adults in Singapore and Japan. Methods Longitudinal data for older adults, aged ≥65 years, from the Panel on Health and Ageing of Singaporean Elderly (PHASE; 2009, 2011–2012, and 2015) and Japan Gerontological Evaluation Study (JAGES; 2010, 2013, and 2016) were used. Dependent variables were being edentate and having a minimal functional dentition (MFD; i.e. ≥20 teeth). The absolute and relative inequalities were calculated using the slope index of inequality (SII) and relative index of inequality (RII) for educational level [low (<6 years); middle (6–12 years); high (>12 years)] in each country. Results A total of 1032 PHASE participants and 35 717 JAGES participants were included. At baseline among PHASE participants, 35.9% were edentate and 24.4% had MFD, while among JAGES participants, 8.5% were edentate and 42.4% had MFD. The prevalence of low, middle and high educational levels for PHASE was 76.5%, 18.0% and 5.5%, and for JAGES were 0.9%, 78.1% and 19.7%, respectively. Older adults in Japan had lower education‐related inequalities for being edentate [for both SII (−0.53, 95% CI = −0.55 to −0.50) and RII (0.40, 95% CI = 0.33–0.48)] and for not having MFD for both SII (−0.24, 95% CI = −0.27 to −0.20) and RII (0.83, 95% CI = 0.79–0.87) compared to Singapore. Conclusions Education‐related inequalities for being edentate and not having MFD were higher among older adults in Singapore compared to Japan.