Exploring the Impact of Behavioral Engagement Indicators on Pain Outcomes in AI-Enabled Musculoskeletal Rehabilitation: A Real-World Investigation.

Abstract

Purpose This study aimed to examine whether behavioral engagement indicators reflecting timing, routine formation, and continuity predict last pain scores of an artificial intelligence (AI)-enabled rehabilitation program in individuals with chronic musculoskeletal (MSK) spinal pain. Methods This ad-hoc analysis of a real-world clinical registry (June 19, 2020 to November 8, 2024) across the United States (N=19,866) included adults with chronic MSK spinal pain undergoing AI-assisted, fully-remote rehabilitation delivered under physical therapists oversight and combining exercise with real-time biofeedback asynchronously monitored, education, and behavior change (lasting up to 12 weeks). Primary outcome was the last pain score, reported through an 11-point Numeric Pain Rating Scale. Behavioral engagement candidate predictors (derived from session log data) comprised early-phase (first three weeks) - treatment initiation (days until first session), early routine formation (consistent weekday session completion), and early continuity (no missed weeks) - and full-period indicators - weekday routine consistency and existence of one-week interruption of sessions (≥7 consecutive days without sessions). Structural equation modeling assessed associations with pain outcomes, adjusted for confounders. Moderation analyses evaluated subgroup differences for baseline pain severity, age, race/ethnicity, and BMI strata. Results All early-phase behavioral engagement indicators - timely treatment initiation, routine formation, and engagement continuity - were associated with lower last pain scores, albeit at very small effect sizes (Cohen's f 2 =0.01). Across the full intervention period, greater consistency in weekday session completion was associated with lower pain (β=-0.21, P 2 =0.02). No moderation was observed for any of the tested subgroups, except for patients with obesity, where a one-week interruption had a stronger effect on pain. Models explained variance was 25%. Conclusion Behavioral engagement indicators capturing treatment initiation, routine formation, and continuity were significantly associated with pain outcomes after AI-enabled MSK rehabilitation, albeit at small magnitude. Behavioral engagement may represent potentially modifiable targets for intervention, requiring further validation.