Socioeconomic status and self-reported, screen-detected and total diabetes prevalence in Chinese men and women in 2011-2012: a nationwide cross-sectional study

BACKGROUND: A rapid epidemiological transition is taking place in China and the association between socioeconomic status (SES) and diabetes prevalence is not clear and may vary by population characteristics and geography within the country. We describe the associations between educational level, annual household living expenditure (AHLE) and diabetes prevalence in a large middle-aged and elderly Chinese population using data from a nationwide cross-sectional study. METHODS: We used data from the China Health and Retirement Longitudinal Study, which collected information from interviews and blood tests from a nationwide sample of people over 44 years of age in 2011-2012. We used multivariable logistic regression to describe the association between highest levels of education (high school or above compared to illiterate) or AHLE (top vs bottom quartile) and self-reported, screen-detected or total diabetes prevalence. We stratified by sex and adjusted for age, education or AHLE (as appropriate), urban, rural or migrant residence status and geographical area. RESULTS: Complete data were available for 10 100 participants of whom 10.5% and 28.9% had the highest and the lowest levels of education respectively. Overall prevalence of self-reported diabetes was 6.0% and of screen-detected diabetes was 9.8%. Higher education level was associated with both self-reported diabetes (odds ratio (OR) = 2.41, 95% confidence interval CI = 1.36-4.46) and total diabetes (OR = 1.53 95%, CI = 1.10-2.15) only in men. AHLE was associated with self-reported diabetes in men (OR = 1.87, 95% CI = 1.26-2.84) and women (OR = 2.31, 95% CI = 1.62-3.34). There was no association between SES and screen-detected diabetes for men or women. CONCLUSIONS: SES inequalities exist in prevalence of diabetes in China and can be used to inform approaches to prevention. Identification and appropriate intervention for people with undiagnosed diabetes is required for all SES groups.