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

Background: 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 14,424 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 age 60 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. The results may have implications for public health interventions targeting populations at risk.