Cardiovascular disease-specific and all-cause mortality across socioeconomic status and lifestyles among patients with established cardiovascular disease in communities of China: data from a national population-based cohort

Background Evidence of socioeconomic status (SES)-related health inequality is scarce in patients with cardiovascular diseases (CVDs) who need both lifestyle change and medical care, particularly in developing countries.Methods The study employed a nationwide population-based cohort design, covering all 31 provinces of Chinese mainland from September 2014 to March 2021. Participants aged 35–75 years with self-reported CVD diagnoses were included. Information on SES and lifestyle details were collected via a questionnaire, and the unequal mortality across SES groups and the mediating effects of lifestyles were explored.Results Among the 104 718 participants included, 27 943 (26.7%) were allocated to high SES, 35 802 (34.2%) were allocated to medium SES and 40 973 (39.1%) were allocated to low SES. During a mean follow-up of 48.9±18.9 months, 5010 deaths were recorded. Participants with low SES had a 65% (HR=1.65, 95% CI: 1.50 to 1.80) greater risk of all-cause death and a 95% (HR=1.95, 95% CI: 1.72 to 2.20) greater risk of CVD death in Chinese communities. A low SES with the worst lifestyle was associated with a significant increase in the risk of all-cause mortality by 172% (HR=2.72, 95% CI: 2.37 to 3.12) and CVD mortality by 218% (HR=3.18, 95% CI: 2.64 to 3.83) compared with a high SES with healthy lifestyle. The joint mediating effects of lifestyles on CVD mortality accounted for 19.6% (95%CI: 14.8% to 24.2%) of the excess mortality risk for individuals with low SES, and these effects varied by genders (p for interaction=0.013) and urbanity (p for interaction=0.004). Leisure-time physical activity was the strongest mediator, followed by dietary factors. For all-cause mortality, outcomes were similar to this.Conclusions Both SES-related health inequalities and lifestyle disparities should be comprehensively considered when caring for this population, and upstream structural interventions that integrate SES and lifestyle factors and are tailored to the target population are urgently needed.Trial registration number NCT02536456.