The association between disease status and health-related quality of life: evidence from a cross-sectional survey across mainland China.

BACKGROUND: This study aimed to assess the health-related quality of life (HRQoL) among Chinese adults with varying disease statuses. METHODS: A cross-sectional study was conducted between June 20 and August 31, 2023 across China. HRQoL was measured using the EQ-5D-5L utility index (UI) and EQ-Visual Analogue Scale (EQ-VAS). Kruskal-Wallis tests compared HRQoL across disease groups, chi-square tests compared problem prevalence within each EQ-5D-5L dimension across disease groups, and Tobit regression examined associations between disease status and HRQoL. Subgroup and interaction analyses assessed effect modification by age, gender, education, employment, and smoking status. RESULTS: A total of 42,447 participants were included (healthy: 33,408; single chronic disease: 5,084; multimorbidity: 3,955). HRQoL showed a clear gradient: median UI and EQ-VAS scores were 1 (0.95-1) and 80 (64–90) in healthy individuals, 0.95 (0.89-1) and 75 (61–83) in the single chronic disease group, and 0.89 (0.73-1) and 69 (54–81) in the multimorbidity group (all P [Formula: see text] 0.001). Problem prevalence differed significantly among groups for all EQ-5D-5L dimensions. Age, education, smoking, and employment status modified associations between disease status and UI, yet single chronic disease and multimorbidity remained consistently linked to lower UI across all subgroups. CONCLUSIONS: HRQoL declined from healthy individuals to those with single chronic disease and multimorbidity. The modifying effects of age, education, smoking, and employment status highlight priority subgroups for targeted interventions. STUDY REGISTRATION: Chinese Clinical Trial Register (ChiCTR), ChiCTR2300072573. Registration Date: June 16, 2023 [Observational study].