Income-related inequality and decomposition of edentulism among aged people in China

Background: The aim of this study was to assess the income-related inequality of edentulism among the aged in China and identify the contributing factors. Methods: A secondary analysis of data from the 4th National Oral Health Epidemiology Survey in China was conducted, and 65–74 years old were selected for the analysis of income-related inequality of edentulism. The concentration curve, Concentration index (CI) and Erreygers-corrected concentration index (EI) were used to represent inequality and its degree qualitatively and quantitatively, respectively. A decomposition method based on probit model was employed to determine the contributors of inequality, including demographic factors, income status, oral health-related knowledge, attitude and practices and self-perceived general health status. Results: In China, aged people with edentulism were concentrated in the poor. The CI was − 0.2337 (95% CIs: − 0.3503, − 0.1170). The EI was − 0.0413 (95% CIs: − 0.0619, − 0.0207). The decomposition results showed that income (75.02%) and oral health-related knowledge, attitude and practices (15.52%) were the main contributors to the inequality. Conclusion: This study showed that pro-poor inequality among the elderly with edentulism existed in China. Corresponding policies against the contributors could be considered to promote the health equality of the elders. © 2022, The Author(s).