Factors associated with socioeconomic inequalities in the use of dental services among Brazilian older adults: an Oaxaca-Blinder decomposition analysis

Abstract

Background: The use of dental services is low among older adults, particularly among vulnerable or disadvantaged groups from various countries. Nonetheless, there is a gap in the literature regarding the factors that contribute to inequalities in the use of dental services. This study aimed to evaluate socioeconomic inequalities in recent and preventive use of dental services among older adults in Brazil and evaluate the factors contributing to these inequalities. Methods: This cross-sectional study used data from the 2019 Brazilian National Health Survey. The dependent variables were the use of recent and preventive dental services (among those who reported using dental services within one year prior to the interview). Socioeconomic status was measured by education level [no formal education vs. some education] and household per capita income [low (≤ 1 minimum wage [MW]) vs. higher (≥ 1 MW)]. Explanatory variables included socioeconomic factors [education, household per capita income]; demographic characteristics [sex; age; living alone; rural residence]; general health status [limitations in basic activities of daily living (BADL); multimorbidity]; and oral health [use of prostheses; self-rated oral health; number of teeth; difficulty eating due to teeth or prostheses; dental insurance]. The Oaxaca-Blinder two-fold decomposition for binary outcomes was used to assess the factors contributing to educational and income-related inequalities in the use and preventive use of dental services. Results: Participants with no formal education and those in the lowest income group had lower recent and preventive use of dental services. The number of teeth was the most significant contributing factor for the observed inequality, accounting for 30.6–51.8% of its increase across models. Difficulty eating made the second largest contribution to the explained inequality gap for preventive use and rural residence contributed to widening the gap for both outcomes. Conclusion: Socioeconomic inequalities in recent and preventive use of dental services among older adults are mainly explained by the number of remaining teeth, but other demographic, oral health, and health service factors play a role.