Use of telehealth and at-home video for remote administration of the North Star Ambulatory Assessment (NSAA): a comparative methods study

Abstract

Remote functional assessments can expand access and reduce burden for families affected by Duchenne muscular dystrophy (DMD), but evidence is needed on the reliability of remote administration and scoring of the North Star Ambulatory Assessment (NSAA). We conducted a non-interventional, mixed‑methods study using a 21 Code of Federal Regulations (CFR) Part 11–compliant video platform to compare NSAA scores from live telehealth versus caregiver‑captured asynchronous at‑home videos and to compare live versus recorded telehealth scoring (Clinical trial number: not applicable). Eighteen participants (mean age 8.7 years) completed NSAA at baseline, 3 months, and 6 months; assessments were double‑scored by NSAA‑certified physical therapists (PT). Mean NSAA was 25.8 (telehealth) versus 25.1 (asynchronous); the 0.82‑point difference met two one‑sided tests for equivalence within ± 3‑point SEM margins ( p < 0.001). Live versus recorded telehealth differed by 0.23 points and was also equivalent ( p < 0.001). Inter‑rater mean absolute difference was 1.87 points (telehealth 1.61; asynchronous 2.15), below the MCID threshold. Remote NSAA was feasible, reliable, and clinically comparable across methods, supporting decentralized follow‑up and data collection in DMD.