Pro-Rich Inequality in Health-Related Quality of Life Among Primary Care Diabetes Patients: A Cross-Sectional Study

This cross-sectional study aimed to assess HRQoL and to examine income-related inequalities among diabetes patients in Harbin, a cold-region city in China, where such evidence remains limited.

In July 2025, 433 adults with diabetes were recruited from two community health centers in Harbin using random sampling from electronic health records. HRQoL was measured using the EuroQol 5-Dimension 5-Level (EQ-5D-5L) utility index and the EuroQol Visual Analogue Scale (EQ-VAS). Income-related inequality was quantified using the concentration index (CI) and the Erreygers-corrected CI. Wagstaff decomposition was applied to identify contributing factors, and horizontal inequity (HI) indices were computed after adjusting for need variables. Sensitivity analyses included Tobit model.

The mean EQ-5D-5L utility index was 0.9303 (SD = 0.1294), and the mean EQ-VAS score was 77.60 (SD = 12.88). Significant pro-rich inequality was observed for both outcomes (standard CI: 0.0093 for EQ-5D-5L and 0.0131 for EQ-VAS; Erreygers index: 0.0249 and 0.0405, respectively). Household income was the largest contributor to inequality, accounting for 73.30% of the inequality in EQ-5D-5L utility index and 53.77% of the inequality in EQ-VAS score. Other notable contributors included blood glucose control, exercise habits, marital status, and digital health literacy for EQ-5D-5L, and adherence to chronic disease follow-up and exercise habits for EQ-VAS. After adjusting for need variables, the HI remained positive for both measures (0.0095 for EQ-5D-5L and 0.0135 for EQ-VAS).

Income-related inequalities in HRQoL were evident among primary care diabetes patients in this cold-region setting. Socioeconomic disparities and modifiable health behaviors are important correlates of HRQoL inequality, warranting further investigation in longitudinal studies.