A novel assessment of participation and executive functions (A-PEX) for traumatic brain injury: a validity study

BACKGROUND: Executive function deficits are a main cause of participation restrictions post-traumatic brain injury (TBI). Assessing executive functions through actual daily participation may provide valuable information for treatment planning and progress. AIM: This study aimed to validate the Assessment of Participation and Executive Functions (A-PEX), a tool for evaluating executive function deficits through actual participation in the inpatient rehabilitation context during the subacute phase following TBI. DESIGN: A cross-sectional with a longitudinal component. SETTING: Inpatient rehabilitation facility. POPULATION: This study included 56 participants divided into two groups: 30 with orthopedic or spinal cord injuries and 26 with TBI. METHODS: Internal consistency was evaluated by Cronbach’s alpha, and test-retest reliability was assessed using interclass correlation coefficients. Known-group construct validity was examined by comparing the A-PEX scores between the two groups, and A-PEX convergent construct validity for patients with TBI was examined using correlations between scores on the A-PEX, Multiple Errands Test-hospital version (MET-HV), and Color Trail Test (CTT). RESULTS: Cronbach’s alpha coefficients for the A-PEX domains ranged between 0.83 and 0.96, indicating good-to-excellent internal consistency. Interclass correlations calculated for the control group indicated moderate test-retest reliability for most A-PEX components. Participants with TBI scored significantly lower than those with orthopedic or spinal cord injury for all A-PEX components (P<0.001). Within the TBI group, significant moderate-to-strong correlations were found between all A-PEX components and the MET-HV (0.52<r<0.73, P<0.05) and between the A-PEX executive function scales and the CTT (r=0.52, P<0.05). CONCLUSIONS: The findings provide evidence for the initial reliability and validity of the A-PEX as a measure of post-TBI executive functions. CLINICAL REHABILITATION IMPACT: By evaluating actual everyday participation, the A-PEX provides valuable clinical insight into the interrelationship between executive functions and participation in the post-TBI subacute phase.