Development of PROWalk: a functional mobility person-reported outcome measure based on the PROMIS adult physical function item bank

IntroductionAssessing an individuals physical capacity to move independently and safely to perform activities of daily living (i.e., functional mobility) can be approached through various modalities, including performance-based physiological tests, observational assessments, and self-report questionnaires. The purpose of this study was to establish a patient-reported outcome measure (PROM), termed PROWalkTM, based on the PROMIS Item Bank 2.0 - Physical Function, to assess perceived mobility challenges, specifically related to gait and balance function, and evaluate its performance in comparison to the Patient-Specific Functional Scale (PSFS) within a population of individuals with sensory peripheral neuropathy. MethodsThe PROWalk PROM was developed with expert clinician input as a custom short form composed of selected items from the Item Bank. Participants with lower extremity peripheral neuropathy who had been prescribed a wearable sensory prosthesis were administered the PROWalk and the PSFS, a perceived functional mobility assessment via telecommunications at baseline and six weeks after wearing the sensory prosthesis. ResultsBoth measures displayed significant increases (i.e., improvements) over time with large effect sizes and upward linear trends for each instrument between baseline and six weeks. When normalized, the measures showed no bias, large limits of agreement, and no normalized change between the instruments. DiscussionThe PROWalk PROM detected significant improvements in perceived functional mobility over time and showed strong temporal stability and suitability for standardized group-level comparisons, which were similar to the PSFS. Overall, the PROWalk appears to be a valid PROM for capturing improvements in self-reported functional mobility related to gait and balance function.