Review: long-term annual conversion rate to dementia was 3.3% in elderly people with mild cognitive impairment.

摘要

QUESTION In elderly people with mild cognitive impairment (MCI), what is the long-term rate of conversion to dementia? REVIEW SCOPE Included studies examined the progression of MCI, defined according to accepted criteria. Outcomes were dementia or probable Alzheimer disease (AD). REVIEW METHODS Medline, EMBASE/Excerpta Medica, and PsycINFO (to Mar 2008) were searched for cohort studies that had 3=5 years of follow-up. 15 studies (n = 2402, mean age 62-82 y) met the selection criteria. Mean follow-up was 6 years (range 5-10 y). MAIN RESULTS The cumulative conversion rate to dementia was 31% (15 studies) and to AD was 33% (11 studies). The table shows annual conversion rates. Annual conversion rates were lower in studies with longer duration of follow-up. CONCLUSION In elderly people with mild cognitive impairment who were followed up for < 10 years, the annual conversion rate to dementia was 3.3%.