Adding delayed recall to the ADAS-cog improves measurement precision in mild Alzheimer's disease: Implications for predicting instrumental activities of daily living.
As research increasingly focuses on preclinical stages of Alzheimer's disease (AD), instruments must be retooled to identify early cognitive markers of AD. A supplemental delayed recall subtest for the Alzheimer's Disease Assessment Scale-cognitive (ADAS-cog; Mohs, Rosen, & Davis, 1983; Rosen, Mohs, & Davis, 1984) is commonly implemented, but it is not known precisely where along the spectrum of cognitive dysfunction this subtest yields incremental information beyond what is gained from the standard ADAS-cog, or whether it can improve prediction of functional outcomes. An item response theory approach can analyze this in a psychometrically rigorous way. Seven hundred eighty-eight patients with AD or amnestic complaints or impairment completed a battery including the ADAS-cog and 2 activities of daily living measures. The delayed recall subtest slightly improved the ADAS-cog's measurement precision in the mild range of cognitive dysfunction and increased prediction of instrumental activities of daily living for individuals with subjective memory impairment.
Department of Psychology, Texas A&M University.
Deborah A
DA
Lowe
Department of Psychology, Texas A&M University.
Steve
S
Balsis
Division of Neuropsychology, Baylor Scott and White Neurosciences Institute.
Jared F
JF
Benge
Alzheimer's Disease and Memory Disorders Center, Department of Neurology, Baylor College of Medicine.
Rachelle S
RS
Doody
D000203:Activities of Daily Living / Q000523:psychology*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000175:diagnosis* / Q000523:psychology; D060825:Cognitive Dysfunction / Q000175:diagnosis* / Q000523:psychology; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D011939:Mental Recall; D008875:Middle Aged; D009483:Neuropsychological Tests; D011594:Psychometrics