title: The utility of a non-verbal prospective memory measure as a sensitive marker for early-stage Alzheimer's disease in Hong Kong.
abstract: BACKGROUND
  With the proportion of older adults in Hong Kong projected to double in size in the next 30 years, it is important to develop measures for detecting individuals in the earliest stage of Alzheimer's disease (AD, 0.5 in Clinical Dementia Rating, CDR). We tested the utility of a non-verbal prospective memory task (PM, ability to remember what one has to do when a specific event occurs in the future) as an early marker for AD in Hong Kong Chinese.
  
  
  METHODS
  A large community dwelling sample of older adults who are healthy controls (CDR 0,N= 125), in the earliest stage of AD (CDR 0.5,N= 125), or with mild AD (CDR 1,N= 30) participated in this study. Their reaction time/accuracy data were analyzed by mixed-factor analyses of variance to compare the performance of the three CDR groups. Logistic regression analyses were performed to test the discriminative power of these measures for CDR 0 versus 0.5 participants.
  
  
  RESULTS
  Prospective memory performance declined as a function of AD severity: CDR 0 > CDR 0.5 > CDR 1, suggesting the effects of early-stage AD and AD progression on PM. After partialling out the variance explained by psychometric measures (e.g., ADAS-Cog), reaction time/accuracy measures that reflected the PM still significantly discriminated between CDR 0 versus 0.5 participants in most of the cases.
  
  
  CONCLUSIONS
  The effectiveness of PM measures in discriminating individuals in the earliest stage of AD from healthy older adults suggests that these measures should be further developed as tools for early-stage AD discrimination.
authors.affiliation: Department of Educational Psychology, The Chinese University of Hong Kong, Hong Kong.
authors.forename: C S
authors.initials: CS
authors.lastname: Tse
authors.affiliation: Department of Psychology, Guangdong University of Education, China.
authors.forename: J F
authors.initials: JF
authors.lastname: Chang
authors.affiliation: Department of Psychiatry, The Chinese University of Hong Kong, Hong Kong.
authors.forename: Ada W T
authors.initials: AWT
authors.lastname: Fung
authors.affiliation: Department of Psychiatry, The Chinese University of Hong Kong, Hong Kong.
authors.forename: Linda C W
authors.initials: LCW
authors.lastname: Lam
authors.affiliation: Department of Educational Psychology, The Chinese University of Hong Kong, Hong Kong.
authors.forename: K T
authors.initials: KT
authors.lastname: Hau
authors.affiliation: Department of Psychiatry, The Chinese University of Hong Kong, Hong Kong.
authors.forename: Grace T Y
authors.initials: GTY
authors.lastname: Leung
authors.affiliation: Department of Psychology and Neurology, Washington University in St. Louis, USA.
authors.forename: D A
authors.initials: DA
authors.lastname: Balota
keywords: Alzheimer’s disease; cognitive testing; memory