Natural history of mild cognitive impairment in older persons

Cognitive abilities of older persons range from normal, to mild cognitive impairment, to dementia. Few large longitudinal studies have compared the natural history of mild cognitive impairment with similar persons without cognitive impairment.

Participants were older Catholic clergy without dementia, 211 with mild cognitive impairment and 587 without cognitive impairment, who underwent annual clinical evaluation for AD and an assessment of different cognitive abilities. Cognitive performance tests were summarized to yield a composite measure of global cognitive function and separate summary measures of episodic memory, semantic memory, working memory, perceptual speed, and visuospatial ability. The authors compared the risk of death, risk of incident AD, and rates of change in global cognition and different cognitive domains among persons with mild cognitive impairment to those without cognitive impairment. All models controlled for age, sex, and education.