Area-level socioeconomic inequalities in hypertension care cascade in China: a nationwide population-based study based on the ChinaHEART project

Background: Socioeconomic status (SES) is one of key social determinants of health. Compared to individual-level SES, the association between area-level SES and hypertension management has been understudied and under-recognised. In this study, we aimed to assess the association between area-level SES and hypertension awareness, treatment, combination therapy and control, and the modification effect of individual characteristics on the associations. Methods: During Dec 2015 and Dec 2022, 1,559,748 residents with hypertension aged 35-75 years from 31 provinces in the China Health Evaluation And risk Reduction through nationwide Teamwork (ChinaHEART) were included. The composite value of area-level SES was generated from national census data and categorized into tertiles. Multivariable mixed models with random effects to account for county-level administrative area were fitted to compute odds ratios (OR) and 95% confidence intervals (CIs) for the independent and interactive associations of both area- and individual-level SES with hypertension management (awareness, treatment, combination therapy and control) and their disparities across different population subgroups. Findings: Among the included participants with hypertension aged 59·1 ± 9·1 years, 794,675 (50·95%), 650,485 (41·70%) and 206,103 (13·21%) were aware, treated, and controlled, respectively. Compared with the high area-level SES group, the low group was significantly associated with a lower odds of hypertension awareness (OR: 0·75, 95% CI: 0·65-0·86), treatment (0·69, 0·59-0·81), combination therapy (0·65, 0·51-0·84), and control (0·62, 0·51-0·75). Participants with low SES at both individual and area level had the lowest odds of hypertension management. Area-level SES had stronger influences on hypertension awareness, treatment and control, but a weaker influence on combination therapy, in the young and those with high individual-level SES. Interpretation: Area-level SES on plays a key role in the awareness, treatment, combination therapy and control of hypertension, with different magnitude of associations. Integrated action to improve area-level circumstances and promote targeted interventions to hypertension care cascade are needed to reduce health inequalities in China. Funding: The CAMS Innovation Fund for Medical Science; the National High Level Hospital Clinical Research Funding; the National Natural Science Foundation of China of China; the Ministry of Finance of China and National Health Commission of China; the 111 Project from the Ministry of Education of China.