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 f2=0.01). Across the full intervention period, greater consistency in weekday session completion was associated with lower pain (β=−0.21, P<0.001), whereas experiencing a full-week interruption predicted higher pain (β=0.14, P<0.001), with small effect sizes (Cohen’s f2=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.