Inequality and Inequity in the Use of Oral Health Services in Australian Adults

Abstract

Objective: Social determinants drive disparities in dental visiting. This study aimed to measure inequality and inequity in dental visiting among Australian adults. Methods: Data were obtained from the National Study of Adult Oral Health (2017 to 2018). Participants were Australian adults aged ≥30 y. The outcome of interest was dental visiting in the last 12 mo. Disparity indicators included education and income. Other sociodemographic characteristics included age, gender, Indigenous status, main language, place of birth, residential location, health card and dental insurance status, and individual’s self-rated and impaired oral health. To characterize inequality in dental service use, we examined bivariate relationships using indices of inequality: the absolute and relative concentration indexes and the slope and relative indexes of inequality. Inequalities were depicted through concentration curves. Indirect standardization with a nonlinear model was used to measure inequity. Results: A total of 9,919 Australian adults were included. Bivariate analysis showed a gradient by education and income on dental visiting, with 48% of those with lowest educational attainment/income having not visited a dentist in the last 12 mo. The concentration curves showed pro–low education and pro–poor income inequalities. All measures of absolute and relative indices were negative, indicating that from the bottom to the top of the socioeconomic ladder (education and income), the prevalence of no dental visiting decreased: absolute and relative concentration index estimates were approximately 2.5% and 5.0%, while the slope and relative indexes of inequality estimates were 14% to 18% and 0.4%, respectively. After need standardization, the group with the highest education or income had almost 1.5-times less probability of not having a dental visit in the previous year than those with the lowest education or income. Conclusion: The use of oral health services exhibited socioeconomic inequalities and inequities, disproportionately burdening disadvantaged Australian adults. Knowledge Transfer Statement: The results of this study can be used by policy makers when planning a dental labor force in relation to the capacity of supply dental services to 1) reduce the inequality and inequity in the use of oral health services and 2) meet identified oral health needs across the Australian population, which is important for preventive dental care.