Inspection time predicts individual differences in everyday functioning among elderly adults: testing discriminant validity.
OBJECTIVE
Inspection time (IT) is a processing speed measure, recently investigated as a biomarker of ageing. This study examined whether earlier IT predicts subsequent problems in everyday functioning in community-dwelling elderly people.


METHODS
Participants completed IT at baseline, 6 months and 18 months. At 42 months, two groups of 15 elderly people matched for education and age (74-88 years) and selected for slower or faster baseline IT, completed a fourth estimate of IT and a practical assessment of everyday functioning (Timed Instrumental Activities of Daily Living - Adelaide).


RESULTS
At 42 months, the group with slower baseline IT had significantly poorer performance (slower completion, higher errors) on more than half of the everyday functioning tasks.


CONCLUSIONS
Slower IT predicts difficulties up to 4 years later in everyday functioning of elderly adults, providing discriminant validation for IT as a biomarker for future changes.
Gregory
Tess
T
School of Psychology, University of Adelaide, Adelaide, South Australia, Australia. tess.gregory@adelaide.edu.au
Callaghan
Adelaide
A
Nettelbeck
Ted
T
Wilson
Carlene
C
D000203:Activities of Daily Living; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D003071:Cognition / Q000502:physiology*; D003936:Diagnosis, Computer-Assisted / Q000592:standards; D004185:Disability Evaluation; D005260:Female; D015577:Geriatric Assessment; D006801:Humans; D008297:Male; D009483:Neuropsychological Tests / Q000592:standards*; D011237:Predictive Value of Tests; D011930:Reaction Time / Q000502:physiology; D015203:Reproducibility of Results; D012111:Residence Characteristics