title: Older adults with limited literacy are at increased risk for likely dementia.
abstract: BACKGROUND
  Low literacy is common among the elderly and possibly more reflective of educational attainment than years of school completed. We examined the association between literacy and risk of likely dementia in older adults.
  
  
  METHODS
  Participants were 2,458 black and white elders (aged 71-82) from the Health, Aging and Body Composition study, who completed the Rapid Estimate of Adult Literacy in Medicine and were followed for 8 years. Participants were free of dementia at baseline; incidence of likely dementia was defined by hospital records, prescription for dementia medication, or decline in Modified Mini-Mental State Examination score. We conducted Cox proportional hazard models to evaluate the association between literacy and incidence of likely dementia. Demographics, education, income, comorbidities, lifestyle variables, and apolipoprotein E (APOE) ε4 status were included in adjusted analyses.
  
  
  RESULTS
  Twenty-three percent of participants had limited literacy (<9th-grade level). Limited literacy, as opposed to adequate literacy (≥9th-grade level), was associated with greater incidence of likely dementia (25.5% vs17.0%; unadjusted hazard ratio [HR] = 1.75, 95% confidence interval 1.44-2.13); this association remained significant after adjustment. There was a trend for an interaction between literacy and APOE ε4 status (p = .07); the association between limited literacy and greater incidence of likely dementia was strong among ε4 noncarriers (unadjusted HR = 1.85) but nonsignificant among ε4 carriers (unadjusted HR = 1.25).
  
  
  CONCLUSIONS
  Limited literacy is an important risk factor for likely dementia, especially among APOE ε4-negative older adults, and may prove fruitful to target in interventions aimed at reducing dementia risk.
authors.affiliation: Sierra Pacific Mental Illness Research, Education, and Clinical Center, San Francisco VA Medical Center, California. Department of Psychiatry, University of California San Francisco. allison.kaup@ucsf.edu.
authors.forename: Allison R
authors.initials: AR
authors.lastname: Kaup
authors.affiliation: National Institute on Aging, Translational Gerontology Branch, Harbor Hospital, Baltimore, Maryland.
authors.forename: Eleanor M
authors.initials: EM
authors.lastname: Simonsick
authors.affiliation: Laboratory of Epidemiology, Demography and Biometry, National Institute on Aging, Bethesda, Maryland.
authors.forename: Tamara B
authors.initials: TB
authors.lastname: Harris
authors.affiliation: Department of Preventive Medicine, University of Tennessee Health Science Center, Memphis.
authors.forename: Suzanne
authors.initials: S
authors.lastname: Satterfield
authors.affiliation: Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, Pennsylvania.
authors.forename: Andrea L
authors.initials: AL
authors.lastname: Metti
authors.affiliation: Department of Epidemiology and Biostatistics and.
authors.forename: Hilsa N
authors.initials: HN
authors.lastname: Ayonayon
authors.affiliation: Department of Epidemiology and Biostatistics and.
authors.forename: Susan M
authors.initials: SM
authors.lastname: Rubin
authors.affiliation: Sierra Pacific Mental Illness Research, Education, and Clinical Center, San Francisco VA Medical Center, California. Department of Psychiatry, University of California San Francisco. Department of Epidemiology and Biostatistics and Department of Neurology, University of California San Francisco.
authors.forename: Kristine
authors.initials: K
authors.lastname: Yaffe
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000523:psychology*; D053327:Apolipoprotein E4 / Q000235:genetics; D015331:Cohort Studies; D003704:Dementia / Q000453:epidemiology / Q000209:etiology* / Q000523:psychology*; D004522:Educational Status; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012307:Risk Factors; D014481:United States / Q000453:epidemiology
chemical_list: D053327:Apolipoprotein E4
keywords: Cognitive aging; Epidemiology.; Risk factors