Reliability and validity testing of the ASSIST functional performance index

Reliability and validity testing of the ASSIST Functional Performance Index (AFPI) was conducted, focusing on persons with physical disabilities (PwPD). The AFPI was iteratively developed to assess persons' needs for Mainstream Smart Home Technologies (MSHT) as Assistive Technology (AT) and to measure the impact of a service delivery model for MSHT. The AFPI consists of 46 items organized by functional domains. A total of N = 22 PwPD completed the AFPI twice. The median response time between these two time points was four days. Test-retest reliability of overall scores was assessed using the Intraclass Correlation Coefficient model (ICC, 3.1). The weighted kappa coefficient was applied to conduct an item analysis, demonstrating moderate to substantial agreement in all but one of the items. During the second administration, validity was established by correlating the number of hours of assistance and total AFPI scores with the SCI-FI Self-Care and Basic Mobility Short Form Questionnaires. Results indicate that the AFPI demonstrates good to very good validity as an assessment tool and outcome measure in recommending and evaluating the impact of MSHT for PwPD. Future studies, including more participants and persons with cognitive and sensory disabilities, may further establish the clinical utility of the AFPI.