Neighborhood socioeconomic status and the prevalence of stroke and coronary heart disease in rural China: A population-based study

Lower neighborhood-level socioeconomic status (SES) is associated with an increased risk of vascular disease in developed countries. Aims: This study aims to identify village- and individual-level determinants of stroke and coronary heart disease (CHD) in a rural Chinese population. Methods: We analyzed data from a population-based survey of 14424 rural Chinese adults aged over 40 years from 54 villages. Primary outcomes were stroke and coronary heart disease (CHD) prevalence. Village-level SES was determined from the Chinese government's official statistical yearbook. Individual-level characteristics were obtained by in-person interviews. Prevalence rate ratios (RRs) and 95% confidence intervals (95% CIs) were calculated using generalized linear mixed models with log-link function to explore associations of village-level SES and individual social, demographic, and cardiovascular risk factors with stroke or CHD. Variance was expressed using the median rate ratio (MRR) and interval rate ratio (IRR). Results: Village accounted for significant variability in the prevalence of stroke (MRR=1·70; 95% CI: 1·42-1·94; P<0·05) and CHD (MRR=1·59; 95% CI: 1·35-1·78, P<0·05), with village-level income alone accounting for 10% and 13·5% of between-village variation in stroke and CHD, respectively. High-income villages were at higher risk of both stroke (RR=1·69, 95% CI: 1·09-2·62) and CHD (RR=1·63, 95% CI: 1·13-2·34) than lower-income villages. Among individual-level risk factors, hypertension was associated with a higher prevalence of stroke (RR=2·33, 95% CI: 1·93-2·80) than CHD (RR=1·58, 95% CI: 1·38-1·82), whereas obesity was only associated with CHD (RR=1·43, 95% CI: 1·23-1·66). In addition, there was an interaction between age and income; residents of higher-income villages below age60 had a higher prevalence of CHD (RR=1·58, 95% CI: 1·15-2·18) but not stroke. Conclusions: There were differences in vascular risk across rural villages in China, with higher lifetime stroke and CHD prevalence in higher-income villages. For CHD, neighborhood effects were stronger among younger residents of high-income villages.