Purpose:
Blindness and poor vision can have a detrimental impact on mental health. In the present study, we examine the relationship between vision, mental well-being, preventive care, and mortality by estimating the direct and indirect effects of self-rated visual impairment (VI) on mortality through mental well-being and preventive care.
Methods:
Using complete data from 12,987 adult participants (≥ age 18 years) of the 2000 Medical Expenditure Panel Survey (MEPS) with mortality linkage through 2006, we undertook structural equation modeling employing two latent variables representing mental well-being and preventive care to examine the effects of self-rated VI on all-cause mortality (Model depicted in Figure). Generalized linear structural equation modeling (GSEM) was used to simultaneously estimate pathways including the latent variables and Cox regression model.
Results:
VI increases the risk of mortality directly after adjusting for mental well-being and preventive care status and other covariates. (HR=1.34; 95% CI: [1.15, 1.57]). Mental well-being and preventive care status both predict mortality (HR=1.58 [1.28, 1.95] and HR=3.58 [2.20, 5.81] respectively). VI adversely affects mental well-being (b= -0.16; p<0.001) but not preventive care practices (b= -0.03; p=0.35). VI increases mortality risk indirectly through mental well-being (HR= 1.07 [1.03, 1.12]). The total effect of VI on mortality including its influence through mental well-being is HR 1.44 [1.23, 1.68].
Conclusions:
Visual impairment directly increases the risk of mortality and also indirectly increases mortality risk slightly through its adverse impact on mental well-being. The persistent increased mortality risk among the visually impaired documented across epidemiologic studies is not due to the impact of VI on reduced preventive care practices.
Keywords: clinical (human) or epidemiologic studies: outcomes/complications