The prevalence of cognitive impairment in an elderly Canadian population.

We investigated cognitive impairment in a study of the health of the elderly population of Saskatchewan. Surveys of elderly persons living at home (n = 1267) and living in long-term care facilities (n = 990) were conducted in 1981. Cognitive impairment was assessed by a short 10-item mental status questionnaire previously validated against a clinical diagnosis of dementia in an elderly Canadian population. The prevalence of clinically significant cognitive impairment was found to increase with age and with dependence level in long-term care facilities. We estimate that 7.8% of the elderly population have cognitive impairment consistent with a clinical diagnosis of dementia. Our estimates are compared with those derived from other studies. These findings affirm the importance of dementia as a cause of dependence in the elderly and the need for long-term care facilities to deal with dementia and its consequences. Also, since at least as many persons with cognitive impairment live at home as in long-term care facilities, health care planners must direct attention to the elderly with dementia at home.