Prediction of driving ability with neuropsychological tests: demographic adjustments diminish accuracy.
Demographically adjusted norms generally enhance accuracy of inferences based on neuropsychological assessment. However, we hypothesized that demographic corrections diminish predictive accuracy for real-world activities with absolute cognitive demands. Driving ability was assessed with a 45-minute drive along a standardized on-road route in participants aged 65+ (24 healthy elderly, 26 probable Alzheimer's disease, 33 Parkinson's disease). Neuropsychological measures included: Trail-Making A and B, Complex Figure, Benton Visual Retention, and Block Design tests. A multiple regression model with raw neuropsychological scores was significantly predictive of driving errors (R2 = .199, p = .005); a model with demographically adjusted scores was not (R2 = .113, p = .107). Raw scores were more highly correlated with driving errors than were adjusted scores for each neuropsychological measure, and among healthy elderly and Parkinson's patients. When predicting real-world activities that depend on absolute levels of cognitive abilities regardless of demographic considerations, predictive accuracy is diminished by demographic corrections.
Barrash
Joseph
J
Department of Neurology, University of Iowa Carver College of Medicine, Iowa City, Iowa, USA. joseph-barrash@uiowa.edu
Stillman
Ashley
A
Anderson
Steven W
SW
Uc
Ergun Y
EY
Dawson
Jeffrey D
JD
Rizzo
Matthew
M
D000368:Aged; D000544:Alzheimer Disease / Q000503:physiopathology*; D001333:Automobile Driver Examination; D001334:Automobile Driving; D005260:Female; D015577:Geriatric Assessment; D006801:Humans; D008297:Male; D008609:Mental Status Schedule; D008960:Models, Psychological; D009483:Neuropsychological Tests; D010300:Parkinson Disease / Q000503:physiopathology*; D011237:Predictive Value of Tests; D011597:Psychomotor Performance / Q000502:physiology*; D013223:Statistics as Topic