title: Changes in memory before and after stroke differ by age and sex, but not by race.
abstract: BACKGROUND
  Post-stroke memory impairment is more common among older adults, women and blacks. It is unclear whether post-stroke differences reflect differential effects of stroke per se or differences in prestroke functioning. We compare memory trajectories before and after stroke by age, sex and race.
  
  
  METHODS
  Health and Retirement Study participants aged ≥50 years (n = 17,341), with no stroke history at baseline, were interviewed biennially up to 10 years for first self- or proxy-reported stroke (n = 1,574). Segmented linear regression models were used to compare annual rates of memory change before and after stroke among 1,169 stroke survivors, 405 stroke decedents and 15,767 stroke-free participants. Effect modification was evaluated with analyses stratified by baseline age (≤70 vs. >70), sex and race (white vs. nonwhite), and using interaction terms between age/sex/race indicators and annual memory change.
  
  
  RESULTS
  Older (>70 years) adults experienced a faster memory decline before stroke (-0.19 vs. -0.10 points/year for survivors, -0.24 vs. -0.13 points/year for decedents, p < 0.001 for both interactions), and among stroke survivors, larger memory decrements (-0.64 vs. -0.26 points, p < 0.001) at stroke and faster memory decline (-0.15 vs. -0.07 points/year, p = 0.003) after stroke onset, compared to younger adults. Female stroke survivors experienced a faster prestroke memory decline than male stroke survivors (-0.14 vs. -0.10 points/year, p < 0.001). However, no sex differences were seen for other contrasts. Although whites had higher post-stroke memory scores than nonwhites, race was not associated with rate of memory decline during any period of time; i.e. race did not significantly modify the rate of decline before or after stroke or the immediate effect of stroke on memory.
  
  
  CONCLUSIONS
  Older age predicted worse memory change before, at and after stroke onset. Sex and race differences in post-stroke memory outcomes might be attributable to prestroke disparities, which may be unrelated to cerebrovascular disease.
authors.affiliation: Department of Epidemiology, University of California, San Francisco, Calif., USA.
authors.forename: Qianyi
authors.initials: Q
authors.lastname: Wang
authors.forename: Iván
authors.initials: I
authors.lastname: Mejía-Guevara
authors.forename: Pamela M
authors.initials: PM
authors.lastname: Rist
authors.forename: Stefan
authors.initials: S
authors.lastname: Walter
authors.forename: Benjamin D
authors.initials: BD
authors.lastname: Capistrant
authors.forename: M Maria
authors.initials: MM
authors.lastname: Glymour
mesh_terms: D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008297:Male; D008568:Memory / Q000502:physiology*; D008569:Memory Disorders / Q000209:etiology*; D008875:Middle Aged; D012307:Risk Factors; D012737:Sex Factors; D020521:Stroke / Q000150:complications*; D017741:Survivors / Q000706:statistics & numerical data