Changes in health inequality for diabetes among middle-aged and older people aged 45 years and older in China from 2011 to 2015: a systematic analysis

Abstract

BackgroundSocioeconomic factors have important roles in the prevalence of diabetes. However, there is insufficient evidence to confirm trends in income-related inequality in diabetes and their determinants. This study aimed to measure income-related health inequality among middle-aged and older patients with diabetes in China from 2011 to 2015, and to determine its causes. MethodsThe data for this study were obtained from the China Health and Retirement Longitudinal Study. A total of 48 519 Chinese patients aged 45 years and older were included (15 457 in 2011, 16 576 in 2013, and 16 486 in 2015). A principal component analysis was performed to measure asset-based economic status. The concentration index was used to measure income-related inequality in patients with diabetes. In addition, we decomposed the concentration index to identify factors that explained wealth-related inequality in patients with diabetes. FindingsThe prevalence of self-reported diabetes was 5·61% (867 of 15 457) in 2011, 7·49% (1241 of 16 576) in 2013, and 8·99% (1482 of 16 486) in 2015. The concentration indices for diabetes were 0·1359 (95% CI 0·0525–0·0597) in 2011, 0·1207 (0·0709–0·0789) in 2013, and 0.1021 (0·0855–0·0942) in 2015, indicative that diabetes affects the rich more than the poor. Decomposition of the concentration index showed that urban area (39·38%), body-mass index (31·16%), education (7·28%), and geographical region (6·09%) were factors that affected health inequality for diabetes in 2015. However, this health inequality decreased with higher age (−29·93%) in 2015. InterpretationThere are health inequities in diabetes in which the disease affects the rich more than the poor. Policies associated with health equity should be facilitated. FundingThis study was funded by the NHC Key Laboratory of Health Economics and Policy Research (Shandong University, Jinan, China) and the National Natural Science Foundation of China (81402761).