Increased mortality risk among the visually impaired: the roles of mental well-being and preventive care practices.

Abstract

Mechanisms by which visual impairment (VI) increases mortality risk are poorly understood. We estimated the direct and indirect effects of self-rated VI on risk of mortality through mental well-being and preventive care practice mechanisms. Using complete data from 12,987 adult participants of the 2000 Medical Expenditure Panel Survey with mortality linkage through 2006, we undertook structural equation modeling using two latent variables representing mental well-being and poor preventive care to examine multiple effect pathways of self-rated VI on all-cause mortality. Generalized linear structural equation modeling was used to simultaneously estimate pathways including the latent variables and Cox regression model, with adjustment for controls and the complex sample survey design. VI increased the risk of mortality directly after adjusting for mental well-being and other covariates (hazard ratio [HR] = 1.25 [95% confidence interval: 1.01, 1.55]). Poor preventive care practices were unrelated to VI and to mortality. Mental well-being decreased mortality risk (HR = 0.68 [0.64, 0.74], P < 0.001). VI adversely affected mental well-being (β = -0.54 [-0.65, -0.43]; P < 0.001). VI also increased mortality risk indirectly through mental well-being (HR = 1.23 [1.16, 1.30]). The total effect of VI on mortality including its influence through mental well-being was HR 1.53 [1.24, 1.90]. Similar but slightly stronger patterns of association were found when examining cardiovascular disease-related mortality, but not cancer-related mortality. VI increases the risk of mortality directly and indirectly through its adverse impact on mental well-being. Prevention of disabling ocular conditions remains a public health priority along with more aggressive diagnosis and treatment of depression and other mental health conditions in those living with VI.