Education and rates of cognitive decline in incident Alzheimer’s disease

• Published in: Journal of neurology, neurosurgery and psychiatry Vol. 77; no. 3; pp. 308 - 316
• Main Authors: Scarmeas, N, Albert, S M, Manly, J J, Stern, Y
• Format: Journal Article
• Language: English
• Published: London BMJ Publishing Group Ltd 01.03.2006; BMJ; BMJ Publishing Group LTD; BMJ Group
• Subjects: Age; Aged; Aged, 80 and over; Alzheimer Disease - diagnosis; Alzheimer Disease - psychology; Alzheimer's disease; Biological and medical sciences; Cognition & reasoning; Cognition Disorders - diagnosis; Cognition Disorders - psychology; cognitive decline; cognitive reserve; Cohort Studies; Degenerative and inherited degenerative diseases of the nervous system. Leukodystrophies. Prion diseases; Dementia; Disease Progression; education; Educational Status; Female; Follow-Up Studies; GEE; generalised estimating equation; HCFA; Headache. Facial pains. Syncopes. Epilepsia. Intracranial hypertension. Brain oedema. Cerebral palsy; Health Care Financing Administration; Higher education; Humans; Hypotheses; incidence; Male; Medical sciences; Mini-Mental State Examination; MMSE; Mortality; Nervous system (semeiology, syndromes); Neurology; Neuropsychological Tests - statistics & numerical data; Population; Prospective Studies; Psychometrics - statistics & numerical data; Sick Role; Statistics as Topic; Studies; Washington Heights and Inwood Aging Project; WAT; WHICAP; Wide Range Achievement Test–Version 3; Word Accentuation Test; WRAT-3; Nervous system diseases; Degenerative disease; Cognitive disorder; Alzheimer disease; Central nervous system disease; Cerebral disorder
• ISSN: 0022-3050; 1468-330X
• DOI: 10.1136/jnnp.2005.072306

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 ⩾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.