TitleMeasurement precision and efficiency of multidimensional computer adaptive testing of physical functioning using the pediatric evaluation of disability inventory
Publication TypeJournal Article
Year of Publication2006
AuthorsHaley, SM, Ni, P, Ludlow, LH, Fragala-Pinkham, MA
JournalArchives of Physical Medicine and Rehabilitation
Date PublishedSep
Publication Languageeng
ISBN Number0003-9993 (Print)
Accession Number16935059
Keywords*Disability Evaluation, *Pediatrics, Adolescent, Child, Child, Preschool, Computers, Disabled Persons/*classification/rehabilitation, Efficiency, Humans, Infant, Outcome Assessment (Health Care), Psychometrics, Self Care

OBJECTIVE: To compare the measurement efficiency and precision of a multidimensional computer adaptive testing (M-CAT) application to a unidimensional CAT (U-CAT) comparison using item bank data from 2 of the functional skills scales of the Pediatric Evaluation of Disability Inventory (PEDI). DESIGN: Using existing PEDI mobility and self-care item banks, we compared the stability of item calibrations and model fit between unidimensional and multidimensional Rasch models and compared the efficiency and precision of the U-CAT- and M-CAT-simulated assessments to a random draw of items. SETTING: Pediatric rehabilitation hospital and clinics. PARTICIPANTS: Clinical and normative samples. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Not applicable. RESULTS: The M-CAT had greater levels of precision and efficiency than the separate mobility and self-care U-CAT versions when using a similar number of items for each PEDI subdomain. Equivalent estimation of mobility and self-care scores can be achieved with a 25% to 40% item reduction with the M-CAT compared with the U-CAT. CONCLUSIONS: M-CAT applications appear to have both precision and efficiency advantages compared with separate U-CAT assessments when content subdomains have a high correlation. Practitioners may also realize interpretive advantages of reporting test score information for each subdomain when separate clinical inferences are desired.