Visual Impairment and All-cause Mortality: A Real-World Retrospective Cohort Study

Chenxi Fu¹Qinyi Gu¹Xi Li²Zhouqian Wang¹Xiaoyu Zhang^3*Wei Chen^4,5*

• ¹Ningbo Eye Hospital, Wenzhou Medical University, Ningbo, China
• ²Shanxi Eye Hospital Affiliated to Shanxi Medical University, Taiyuan, China
• ³School of Public Health, Wenzhou Medical University, Wenzhou, China
• ⁴National Clinical Research Centre for Ocular Diseases, Eye Hospital, Wenzhou Medical University, Wenzhou, 325027, PR China, Wenzhou, China
• ⁵Ningbo Key Laboratory of Medical Research on Blinding Eye Diseases, Ningbo Eye Institute, Ningbo Eye Hospital, Wenzhou Medical University, Ningbo, China

Background: VI (visual impairment) significantly impacts global public health, and there are few studies and inconsistent results on the impact of VI on mortality in Chinese adults. Our study aims to investigate the association between VI and the all-cause mortality risk in Chinese adults and to explore potential sex differences. Methods: This retrospective cohort (from July 17, 2010 to September 30, 2021) utilized data from the Yinzhou Health Information System, involving 182,468 individuals with valid visual acuity (VA) examination records. We assessed VI, defined as a presenting VA of the better eye worse than 0.5, using two variables: a binary variable (non-VI vs. VI) and a categorical variable (non-VI: VA ≥ 0.5; mild VI: 0.3 ≤ VA < 0.5; moderate VI: 0.1 ≤ VA < 0.3; severe VI: VA < 0.1). Cox proportional hazards multivariable regression models were used to estimate the hazard ratios (HRs) and 95% confidence intervals (CIs) for the all-cause mortality risk. Subgroup analyses were also conducted based on sex and age. Results: During a median follow-up of 3.87 years, there were 2,632 death events, with 1,579 occurring in the non-visual impairment (VI) group and 1,053 in the VI group. Individuals with VI (VA < 0.5) had an increased all-cause mortality risk (HR, 1.15; 95% CI, 1.06–1.24), and this association persisted in the elderly (HR, 1.15; 95% CI, 1.06–1.25). Old females with moderate or severe VI showed significantly higher all-cause mortality risks, with HRs of 1.32 (95% CI, 1.13–1.55) and 2.16 (95% CI, 1.35–3.46), respectively. Among old male participants, the increased all-cause mortality risk was only observed in those with moderate VI (HR, 1.42; 95% CI, 1.23–1.65). Conclusions: VI was associated with an increased all-cause mortality risk in Chinese elderly individuals. Sex differences were also observed in the associations between the VI level and the all-cause mortality risk.