Prevalence and outcomes of vascular cognitive impairment

Objective: To assess the importance of vascular cognitive impairment and it s three subgroups (cognitive impairment, no dementia; vascular dementia; an d AD with a vascular component) to the prevalence and burden of cognitive i mpairment in elderly people. Background: Vascular lesions may produce a spe ctrum of cognitive changes, Omitting elderly patients whose cognitive impai rment falls short of dementia (vascular cognitive impairment, no dementia) may give a falsely low indication of the prevalence and burden of disease. To test this proposition, we compared the rates of adverse outcomes for pat ients with no cognitive impairment, vascular cognitive impairment (and its subgroups), and probable AD. Methods: The Canadian Study of Health and Agin g is a prospective cohort study of 10,253 randomly selected community-dwell ing and institution-dwelling respondents aged 65 years or older. In the com munity, all participants (n = 9,008) were screened for cognitive impairment ; those who screened positive and a sample of those who screened negative r eceived a clinical assessment (n = 1,659). All patients living in instituti ons received a clinical assessment (n = 1,255). Participants were reassesse d 5 years after the original survey. Results: Vascular cognitive impairment without dementia was the most prevalent form of vascular cognitive impairm ent among those aged 65 to 84 years. Rates of institutionalization and mort ality for those with vascular cognitive impairment were significantly highe r than those of people who had no cognitive impairment, and the mortality r ate for patients with vascular cognitive impairment was similar to that of patients with AD. Conclusions: Failure to consider vascular cognitive impai rment without dementia underestimates the prevalence of impairment and the risk for adverse outcomes associated with vascular cognitive impairment.