Abstract
Purpose: :
To describe the prevalence of self-reported visual impairment in elderly Canadians and to examine its association with selected socio-demographic and health factors.
Methods: :
Subjects were participants in phase I clinical examination of the Canadian Study of Health and Aging. Vision state was ascertained from a self-reported question: "How is your eyesight (with glasses or contacts if you wear them)?" Response of "Poor" to this question was considered as poor vision and response of "Unable to see" as blindness. Cognitive impairment with or without dementia was diagnosed by neurologists and neuropsychologists after comprehensive clinical examinations and neuropsychological tests. Stroke was diagnosed by history or clinical examination by neurologists. Other information was collected from in-person interview or clinical examination. Standardized weights were used in all analyses.
Results: :
Analyses included 2671 participants living in community and institutions with a median age 72 years. The overall prevalence was 6.2% for poor vision, 0.7% for blindness and 6.8% for either. Higher prevalences were seen in women and people aged 85 years or older. Participants with education ≤ 6 years were two times more likely to report visual impairment. Institutional residents, people with falls or a depressed mood were about three times more likely to state poor vision or blindness. Individuals with smoking were associated with about four times odds of visual impairment. Persons with difficulty of everyday activities or with a self-rated poor health were about seven and 15 times more likely to report visual impairment. Compared to participants with neither stroke nor cognitive impairment, the adjusted odds ratio (OR) of visual impairment was 1.8 (95% confidence interval 1.1-2.8) for cognitive impairment alone, 3.8 (95% confidence interval 1.5-9.4) for stroke alone and 8.3 (95% confidence interval 4.9-14.2) for both stroke and cognitive impairment. The observed joint OR (8.3) differed largely from the one (4.6) expected from the additive model, suggesting an additive interaction.
Conclusions: :
Visual impairment in elderly Canadians is common and is associated with increased odds of institutionalization, frequent falls, difficulty of everyday activities and poor health. Good eyesight may imply good health and good independence in elderly. The association of cognitive impairment and visual impairment may be modified by stroke in an additive fashion.
Keywords: clinical (human) or epidemiologic studies: prevalence/incidence • clinical (human) or epidemiologic studies: risk factor assessment • clinical (human) or epidemiologic studies: outcomes/complications