Longitudinal associations between self-reported vision impairment and all-cause mortality: a nationally representative cohort study among older Chinese adults

OBJECTIVE: To compare the effects of pre-existing and new self-reported vision impairment (VI), and its correction, on all-cause mortality among Chinese adults aged 45 years and older. METHODS: We used four waves of data from the China Health and Retirement Longitudinal Study. Our analytical cohort consists of 15 808 participants aged 45 years and older with an average follow-up of 6.4 years. Exposures included pre-existing self-reported VI and vision correction (time‐independent exposures), new self-reported VI and vision correction (time‐dependent exposures). Outcomes were measured as the risk of all-cause mortality and the risk stratification for pre-specified factors. RESULTS: Compared with participants with normal vision, all-cause mortality was higher among those with pre-existing self-reported VI (crude HR (cHR)=1.29, 95% CI: 1.17 to 1.44; adjusted HR (aHR)=1.22, 95% CI: 1.09 to 1.37) and new self-reported VI (cHR=1.42, 95% CI: 1.28 to 1.58; aHR=1.36, 95% CI: 1.21 to 1.51). Mortality risk was lower among those with high school or higher education. Participants who were wearing eyeglasses/contact lenses or had cataract surgery at baseline did not have significantly higher all-cause mortality (eyeglasses: aHR=0.82, 95% CI: 0.65 to 1.02; cataract surgery: aHR=1.12, 95% CI: 0.74 to 1.69) compared with participants with normal vision. The same was true among participants with new correction of self-reported VI (glasses: aHR=1.01, 95% CI: 0.78 to 1.24; cataract surgery: aHR=0.95, 95% CI: 0.68 to 1.31). CONCLUSIONS: Both pre-existing and new self-reported VI increase all-cause mortality among Chinese adults aged 45 years and older, though visual correction reduces this risk.