|Measurement precision and efficiency of multidimensional computer adaptive testing of physical functioning using the pediatric evaluation of disability inventory
|Year of Publication
|Haley, SM, Ni, P, Ludlow, LH, Fragala-Pinkham, MA
|Archives of Physical Medicine and Rehabilitation
|*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.