Disability and 6-year mortality in elderly population. Role of visual impairment

We investigated the prevalence of visual impairment (VI), its determinants and its association with Activities of Daily Living (ADL), Instrumental Activities of Daily Living (IADL), Gross Mobility (GM) and 6-year mortality in elderly subjects. A cross-sectional survey in a large population randomly selected in 1992 with a 6-year mortality evaluation in Campania, a region in southern Italy.

A random sample of 1332 elderly subjects aged 65 to 95 years (mean age 74.2 +/- 6.4), selected from the electoral rolls, was interviewed by trained physicians. Self-reported visual function, socio-demographic and clinical characteristics were recorded. Disability was assessed by measuring ability in ADL, IADL and GM.

VI was found to affect 34% of this population, with an age-related increase of mild and severe VI. VI affects ADL, IADL and GM disability. Age, diabetes and low educational level, but not comorbidity or hypertension, proved to be predictors of VI. Mortality increased with severity of VI in 38.1% of subjects with severe functional impairment (p < 0.001). The presence of VI was seen to increase the risk of mortality by 1.40 (95% CI 1.07-1.84), independently of age, sex, comorbidity, diabetes, hypertension or disability.

This study demonstrates an association between visual impairment and disability in an elderly population, and the predictive effect of visual impairment on mortality independently of comorbidity. These results illustrate the need to eradicate avoidable blindness, in order to improve the quality of life and to prolong survival of the elderly.