title: Assessing mobility in children using a computer adaptive testing version of the pediatric evaluation of disability inventory.
abstract: OBJECTIVE
  To assess score agreement, validity, precision, and response burden of a prototype computerized adaptive testing (CAT) version of the Mobility Functional Skills Scale (Mob-CAT) of the Pediatric Evaluation of Disability Inventory (PEDI) as compared with the full 59-item version (Mob-59).
  
  
  METHODS
  Computer simulation analysis of cross-sectional and longitudinal retrospective data; and cross-sectional prospective study.
  
  
  METHODS
  Pediatric rehabilitation hospital, including inpatient acute rehabilitation, day school program, outpatient clinics, community-based day care, preschool, and children's homes.
  
  
  METHODS
  Four hundred sixty-nine children with disabilities and 412 children with no disabilities (analytic sample); 41 children without disabilities and 39 with disabilities (cross-validation sample).
  
  
  METHODS
  Not applicable.
  
  
  METHODS
  Summary scores from a prototype Mob-CAT application and versions using 15-, 10-, and 5-item stopping rules; scores from the Mob-59; and number of items and time (in seconds) to administer assessments.
  
  
  RESULTS
  Mob-CAT scores from both computer simulations (intraclass correlation coefficient [ICC] range, .94-.99) and field administrations (ICC=.98) were in high agreement with scores from the Mob-59. Using computer simulations of retrospective data, discriminant validity, and sensitivity to change of the Mob-CAT closely approximated that of the Mob-59, especially when using the 15- and 10-item stopping rule versions of the Mob-CAT. The Mob-CAT used no more than 15% of the items for any single administration, and required 20% of the time needed to administer the Mob-59.
  
  
  CONCLUSIONS
  Comparable score estimates for the PEDI mobility scale can be obtained from CAT administrations, with losses in validity and precision for shorter forms, but with a considerable reduction in administration time.
authors.affiliation: Health and Disability Research Institute, Boston University, Boston, MA, USA. smhaley@bu.edu
authors.forename: Stephen M
authors.initials: SM
authors.lastname: Haley
authors.forename: Anastasia E
authors.initials: AE
authors.lastname: Raczek
authors.forename: Wendy J
authors.initials: WJ
authors.lastname: Coster
authors.forename: Helene M
authors.initials: HM
authors.lastname: Dumas
authors.forename: Maria A
authors.initials: MA
authors.lastname: Fragala-Pinkham
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D003198:Computer Simulation; D003430:Cross-Sectional Studies; D004185:Disability Evaluation; D019988:Children with Disabilities / Q000534:rehabilitation*; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D017063:Outcome Assessment, Health Care / Q000379:methods*; D012046:Rehabilitation / Q000592:standards*; D012047:Rehabilitation Centers; D012680:Sensitivity and Specificity