title: Predictors of progression to severe Alzheimer's disease in an incidence sample.
abstract: BACKGROUND
  Little is known about factors influencing time to severe Alzheimer's disease (AD).
  
  
  METHODS
  Incident cases of AD in the cache county memory study were identified. Severe AD was defined as mini-mental state examination score of ≤10 or Clinical Dementia Rating Scale score of 3; cases with either mini-mental state examination score of ≥16 or clinical dementia rating <2 were not categorized as severe AD. Kaplan-Meier, log-rank tests, and Cox analyses were used to identify demographic, clinical, and genetic correlates of time to progression to severe AD.
  
  
  RESULTS
  Sixty-eight of 335 cases of incident AD developed severe dementia. In bivariate analyses, female gender, less than high school education, at least one clinically significant Neuropsychiatric Inventory domain at baseline, and the youngest and oldest ages exhibited shorter time to severe AD. In competing risk analysis, subjects with mild or at least one clinically significant neuropsychiatric inventory domain score, and subjects with worse health were more likely to progress to severe dementia or death.
  
  
  CONCLUSIONS
  Demographic and clinical variables predict progression to severe AD. Further study should examine whether these relationships are causal or correlational.
authors.affiliation: Department of Psychiatry and Behavioral Sciences, Johns Hopkins School of Medicine, Baltimore, MD, USA. pvrabins@jhmi.edu
authors.forename: Peter V
authors.initials: PV
authors.lastname: Rabins
authors.forename: Sarah
authors.initials: S
authors.lastname: Schwartz
authors.forename: Betty S
authors.initials: BS
authors.lastname: Black
authors.forename: Christopher
authors.initials: C
authors.lastname: Corcoran
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Fauth
authors.forename: Michele
authors.initials: M
authors.lastname: Mielke
authors.forename: Jessica
authors.initials: J
authors.lastname: Christensen
authors.forename: Constantine
authors.initials: C
authors.lastname: Lyketsos
authors.forename: Joann
authors.initials: J
authors.lastname: Tschanz
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000523:psychology*; D018450:Disease Progression; D005260:Female; D006801:Humans; D008297:Male; D009483:Neuropsychological Tests; D012307:Risk Factors