Predicting cognitive change in older adults: the relative contribution of practice effects.
Assessing cognitive change in older adults is a common use of neuropsychological services, and neuropsychologists have utilized several strategies to determine if a change is "real," "reliable," and "meaningful." Although standardized regression-based (SRB) prediction formulas may be useful in determining change, SRBs have not been widely applied to older adults. The current study sought to develop SRB formulas on a group of 127 community-dwelling older adults for several widely used neuropsychological measures. In addition to baseline test scores and demographic information, the current study also examined the role of short-term practice effects in predicting test scores after 1 year. Consistent with prior research on younger adults, baseline test performances were the strongest predictors of future test performances, accounting for 25%-58% of the variance. Short-term practice effects significantly added to the predictability of all nine of the cognitive tests examined (3%-22%). Future studies should continue extending SRB methodology for older adults, and the inclusion of practice effects appears to add to the prediction of future cognition.
Duff
Kevin
K
Department of Neurology, University of Utah, Utah 84108, USA. kevin.duff@hsc.utah.edu
Beglinger
Leigh J
LJ
Moser
David J
DJ
Paulsen
Jane S
JS
Schultz
Susan K
SK
Arndt
Stephan
S
D000368:Aged; D000369:Aged, 80 and over; D003071:Cognition; D005260:Female; D015577:Geriatric Assessment / Q000379:methods; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D009483:Neuropsychological Tests; D011214:Practice, Psychological; D011237:Predictive Value of Tests; D012044:Regression Analysis