A pragmatic, decentralized trial of the home-based InTandem ^® neurorehabilitation system: analyses of engagement, safety, and effectiveness from the OrcHESTRAS trial

Abstract Background Chronic stroke-related gait impairment remains a major source of disability. InTandem is an autonomous neurorehabilitation system delivering individualized, progressive rhythmic auditory stimulation for home-based gait rehabilitation. Objectives To evaluate: (1) engagement during a 12-week autonomous, home-based intervention, (2) changes in walking endurance and functional mobility, and (3) outcome differences across pre-defined engagement and baseline speed subgroups. Methods This pragmatic, decentralized trial enrolled adults ≥6 months post-stroke with residual gait deficits. Participants were asked to complete 30-minute sessions 3x/week for up to 12 weeks. Engagement was primarily assessed as the proportion achieving moderate-to-high weekly usage (> 4 weeks; benchmark p1 = 0.60). Changes in 6-Minute Walk Test (6MWT) distances and Timed Up and Go (TUG) times were analyzed using linear mixed-effects models. Results Of the 204 who initiated the intervention, 81.9% (95% CI [0.76-0.87]) engaged at least 4 weeks, meeting the primary endpoint (p < 0.001). Overall, 58.1% achieved high engagement (> 9 weeks), 23.9% moderate engagement (4-8 weeks), and 18.1% low engagement (≤3 weeks). Significant improvements in 6MWT distance (+ 26.1 ±5.6 m; 95% CI [14.99, 37.22]) and TUG times (−1.45±0.31 s; 95% CI [−2.06, −0.84]) (p < 0.001) were observed. Engagement influenced effectiveness: each additional week engaged predicted a 5.82 m greater gain in the 6MWT (SE = 2.05; 95% CI [1.77, 9.87], p < 0.005). Conclusions Autonomous home-based delivery of music-based rhythmic auditory stimulation achieved moderate-to-high engagement and improved walking endurance and functional mobility, supporting InTandem as a scalable approach to chronic stroke gait rehabilitation. Trial registration Trial registration: Clinicaltrials.gov NCT06051539 . Registered on 20 September 2023. https://clinicaltrials.gov/study/NCT06051539