Physical Abilities and Mobility Scale: reliability and validity in children receiving inpatient rehabilitation for acquired brain injury.

Abstract Objective To investigate the psychometric properties of the Physical Abilities and Mobility Scale (PAMS) in children receiving inpatient rehabilitation for acquired brain injury (ABI). Design Admission and discharge PAMS item and total scores were evaluated. The WeeFIM was used as the criterion standard. A case study was used to illustrate the complementary nature of the PAMS and WeeFIM. Setting A single, free-standing, academically affiliated pediatric rehabilitation hospital. Participants Children (N=107) aged 2 through 18 years receiving inpatient rehabilitation for ABI between March 2009 and March 2012. Forty-two additional children treated during this time were excluded because of missing PAMS data. Interventions Not applicable. Main Outcome Measures Internal consistency was evaluated using Cronbach alpha. Interrater reliability was evaluated through overall agreement, Pearson correlations, and intraclass correlations. Construct validity was examined through exploratory factor analysis. Criterion validity was explored through correlations of PAMS overall and factor scores with WeeFIM total and subscale scores. Sensitivity to recovery was examined using paired t tests, examining differences between admission and discharge scores for each item and for the total score. Results Internal consistency and interrater reliability were high. Factor analysis revealed 2 factors: lower-level skills and higher-level mobility skills. Correlations with the WeeFIM ranged from moderate to very strong; total PAMS score most strongly correlated with the WeeFIM mobility subscore. Total PAMS score and each item score significantly increased between admission and discharge. Conclusions The PAMS is a reliable and valid measure of progress during inpatient rehabilitation for children with ABI. By capturing fine-grain progress toward both lower-level and higher-level mobility skills, the PAMS complements the WeeFIM in assessing functional gains during the rehabilitation stay.