Socioeconomic Inequalities in Oral Frailty and Its Components.

OBJECTIVES

Oral frailty, an intermediate stage between healthy and declined oral function, involves impairments such as tooth loss and chewing difficulty. Socioeconomic conditions may influence oral frailty risk. This study examined the socioeconomic inequalities in oral frailty and its components among older adults in Japan.

METHODS

This cross-sectional study used 2022 questionnaire data from the Japan Gerontological Evaluation Study of adults aged ≥ 65 years. Dependent variables included oral frailty and its five components. Oral frailty was defined as having ≥ 2 of the following: fewer teeth, dry mouth, and difficulty in chewing, swallowing, or speaking. Independent variables were socioeconomic factors, comprising educational attainment, income, wealth, and pension type. Age and sex were adjusted as confounders. The Slope Index of Inequality (SII) and Relative Index of Inequality (RII) were estimated after applying multiple imputation to address missing data.

RESULTS

A total of 21,924 older adults were included. The prevalence of oral frailty was 33.6%. Significant inequalities were identified across all socioeconomic factors. Wealth showed the greatest inequality, with an adjusted SII of 0.17 (95% confidence interval (CI): 0.14-0.20) and RII of 1.66 (95% CI: 1.52-1.82).

CONCLUSIONS

Substantial socioeconomic inequalities in oral frailty were observed, with wealth being the most influential factor.