Education and rates of cognitive decline in incident Alzheimer's disease.
BACKGROUND
Some (but not all) epidemiological studies have noted faster rates of progression in high education patients with Alzheimer's disease (AD), which has been attributed to harbouring/tolerating a higher pathological burden at the time of clinical dementia for subjects with higher education. We wanted to assess the relationship between education and rates of decline in AD.


METHODS
During the course of a community based multiethnic prospective cohort study of individuals aged > or = 65 years living in New York, 312 patients were diagnosed with incident AD and were followed overall for 5.6 (up to 13.3) years. The subjects received an average of 3.7 (up to 9) neuropsychological assessments consisting of 12 individual tests. With the aid of a normative sample, a standardised composite cognitive score as well as individual cognitive domain scores were calculated. Generalised estimating equation models were used to examine the association between education and rates of cognitive decline.


RESULTS
Composite cognitive performance declined by 9% of a standard deviation per year. Rates of decline before and after AD incidence were similar. For each additional year of education there was 0.3% standard deviation lower composite cognitive performance for each year of follow up. The association between higher education and faster decline was noted primarily in the executive speed (0.6%) and memory (0.5%) cognitive domains and was present over and above age, gender, ethnicity, differential baseline cognitive performance, depression, and vascular comorbidity.


CONCLUSIONS
We conclude that higher education AD patients experience faster cognitive decline.
Cognitive Neuroscience Division, Taub Institute for Research in Alzheimer's Disease and the Aging Brain, Columbia University Medical Center, 622 West 168th Street, PH 19th Floor, New York, NY 10032, USA. ns257@columbia.edu
N
N
Scarmeas
S M
SM
Albert
J J
JJ
Manly
Y
Y
Stern
D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000175:diagnosis* / Q000523:psychology; D003072:Cognition Disorders / Q000175:diagnosis* / Q000523:psychology; D015331:Cohort Studies; D018450:Disease Progression; D004522:Educational Status; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D009483:Neuropsychological Tests / Q000706:statistics & numerical data*; D011446:Prospective Studies; D011594:Psychometrics / Q000706:statistics & numerical data; D012803:Sick Role; D013223:Statistics as Topic