Kumar B. Rajan|Robert S. Wilson|Jennifer Weuve|Lisa L. Barnes|Denis A. Evans
Cognitive impairment 18 years before clinical diagnosis of Alzheimer disease dementia
Rush University Medical Center|Rush University Medical Center|Rush University Medical Center|Rush University Medical Center|Rush University Medical Center
examine relation performance brief cognitive tests development clinically diagnosed alzheimer disease ad dementia following 18 years sample african americans european americansa composite cognitive test score based tests episodic memory executive function global cognition constructed prospective populationbased sample 2125 participants 55 african american 61 female aged 65 years older residing 4 chicago neighborhoods time ad dementia diagnosis categorized 6 groups corresponding data collection periods 0109 1039 4069 7099 100129 130179 yearsof 2125 participants without clinical ad dementia 442 21 developed clinical ad dementia 18 years followup lower composite cognitive test scores associated development ad dementia duration study magnitude association composite cognitive test score development ad dementia increased odds ratio 339 95 confidence interval 172 667 p 0001 130179 years 984 95 confidence interval 741 1306 p 0001 0109 years per sd increment associations consistently larger among european americans among african americans performance individual cognitive tests episodic memory executive function global cognition also significantly predicted development ad dementia associations exhibiting similar trend 18 yearsour findings suggest cognitive impairment may manifest preclinical phase ad dementia substantially earlier previously established