Visual impairment, age-related cataract, and mortality

Objective: To explore associations between visual impairment, cataract, and mortality in older persons after adjusting for other factors associated wi th mortality. Methods: A population cohort of 3654 persons aged 49 years or older (82.4% of eligible residents in the Blue Mountains region, west of Sydney, Austral ia), were examined at the Blue Mountains Eye Study baseline period (1992-19 94) and followed up 5 years later (1997-1999). Australian National Death In dex data were used to confirm persons who had died since baseline. Associat ions between mortality and presence of visual impairment and cataract at ba seline were assessed using the Cox proportional hazards regression model, c ontrolling for age, sex, demographic and socioeconomic status, medical hist ory, and health risk behaviors. Results: By June 30, 1999, 604 participants (16.5%) had died. The age- and sex-standardized 7-year cumulative mortality rate was 26% among persons wit h any visual impairment and 16% in persons without visual impairment. After adjusting for factors found significantly associated with mortality, inclu ding age, male sex, low self-rated health, low socioeconomic status, system ic medical conditions, and negative health risk behaviors, the presence at baseline of any visual impairment was independently associated with increas ed mortality risk (risk ratio [RR], 1.7; 95% confidence interval, 1.2-2.3). The presence of age-related cataract, either nuclear (RR, 1.5), cortical ( RR, 1.3), or posterior subcapsular cataract (RR, 1.5), was also significant ly associated with increased mortality risk. These associations remained st atistically significant when visual impairment and each type of cataract we re included simultaneously in the multivariate Cox model. Conclusion: Visual impairment and age-related cataract may be independent r isk factors for increased mortality in older persons.