Associations of Social Determinants of Health Scores with Visual Impairment and Premature Death in Visually Impaired Adults: Insights from CHARLS—A Cohort Study

Background: The prevalence of vision impairment (VI) has been increasing worldwide. However, limited population-based evidence currently exists on the relationship between VI and social determinants of health (SDH) scores in China. Even less is known about the association between SDH scores and early death, especially in people with VI. This study aimed to evaluate the association between SDH scores and VI, and further examine whether SDH scores were associated with premature mortality among middle-aged and older Chinese adults with VI. Methods: Data from the China Health and Retirement Longitudinal Study (CHARLS) were analyzed in this study. We examined the association between SDH scores and VI among 2559 adults aged ≥ 45 years, and further assessed the relationship between SDH scores and premature death in 8612 individuals aged ≥ 45 years with VI. Statistical analyses included Kaplan–Meier curves, Cox proportional hazards models, restricted cubic spline (RCS) analyses, subgroup analyses, and sensitivity analyses. Results: Kaplan–Meier analysis revealed that individuals with higher SDH scores had a lower risk of experiencing VI compared to those with lower SDH scores (log-rank test p < 0.001). Similarly, among individuals with VI, higher SDH scores were consistently associated with a reduced probability of premature death (log-rank test p < 0.001). In the fully adjusted model, each unit increment in SDH score was associated with a 6% lower risk of VI (HR = 0.94, 95% CI: 0.91–0.98, p = 0.002) and a 15% lower risk of premature death (HR = 0.85, 95% CI: 0.78–0.93, p < 0.001). Conclusions: Among Chinese adults aged ≥45 years, higher SDH scores were significantly correlated with a lower risk of VI. Furthermore, low SDH scores were associated with an increased risk of premature death in those with VI. These findings highlight the association between SDH and lower VI risk as well as longer life expectancy for individuals already living with VI among middle-aged and older populations.