Socioeconomic disparity in mortality and the burden of cardiovascular disease: analysis of the Prospective Urban Rural Epidemiology (PURE)-China cohort study

Background Although socioeconomic inequality in cardiovascular health has long been a public health focus, the differences in cardiovascular-disease burden and mortality between people with different socioeconomic statuses has yet to be adequately addressed. We aimed to assess the effects of socioeconomic status, measured via three socioeconomic-status indicators (ie, education, occupation, and household wealth and a composite socioeconomic-status disparity index, on mortality and cardiovascular-disease burden (ie, incidence, mortality, and admission to hospital) in China. Methods For this analysis, we used data from the Prospective Urban Rural Epidemiology (PURE)-China cohort study, which enrolled adults aged 35-70 years from 115 urban and rural areas in 12 provinces in China between Jan 1, 2005, and Dec 31, 2009. Final follow-up was on Aug 30, 2021. Indicators of socioeconomic status were education, occupation, and household wealth; these individual indicators were also used to create an integrated socioeconomic-status index via latent class analysis. Standard questionnaires administered by trained researchers were used to obtain baseline data and were supplemeted by physical measurements. The primary outcomes were all-cause mortality, cardiovascular disease mortality, non-cardiovascular-disease mortality, major cardiovascular disease, and cardiovascular-disease admission to hospital. Hazard ratios (HRs) and average marginal effects were used to assess the association between the primary outcomes and socioeconomic status.Findings Of 47 931 participants enrolled in the PURE-China study, 47 278 (98 center dot 6%) had complete information on sex and follow-up. After excluding 1189 (2 center dot 5%) participants with missing data on education, household wealth, and occupation at baseline, 46 089 participants were included in this analysis. Median follow-up was 11 center dot 9 years (IQR 9 center dot 5-12 center dot 6); 26 860 (58 center dot 3%) of 46 089 participants were female and 19 229 (41 center dot 7%) were male. Having no or primary education, unskilled occupation, or being in the lowest third of household wealth was associated with a higher risk of all-cause mortality, cardiovascular-disease mortality, non-cardiovascular-disease mortality, major cardiovascular disease, and cardiovascular-disease admission to hospital compared with having higher education, a professional or managerial occupation, or more household wealth. After adjustment for confounders, people categorised as having low integrated socioeconomic status based on the index had a higher risk of all-cause mortality (HR 1 center dot 65 [95% CI 1 center dot 42-1 center dot 92]), cardiovascular-disease mortality (2 center dot 19 [1 center dot 68-2 center dot 85]), non-cardiovascular disease mortality (1 center dot 43 [1 center dot 18-1 center dot 72]), major cardiovascular disease (1 center dot 43 [1 center dot 27-1 center dot 61]) and cardiovascular-disease admission to hospital (1 center dot 14 [1 center dot 01-1 center dot 28]) compared with people categorised as having high integrated socioeconomic status. Interpretation Socioeconomic-status inequalities in mortality and cardiovascular-disease outcomes exist in China. Targeted policies of equal health-care resource allocation should be promoted to equitably benefit people with fewer years of education and less household wealth.