Therapist effects in real-world rehabilitation outcomes: a cohort study of the nationwide GLA:D osteoarthritis management programme in Denmark
Philips Edomwonyi Obasohan, Joe Palmer, David Alderson, Dahai Yu, Dorte T Grønne, Ewa M Roos, Søren T Skou, George M PeatObjective
Unlike several other fields of healthcare, little is known about the size of ‘therapist effects’ on patient outcomes following rehabilitation for musculoskeletal conditions. We aimed to estimate the proportion of variance in patient outcomes from a structured rehabilitation programme explained by therapist effects.
Methods
For our observational cohort study, we accessed data from the national multicentre Good Life with osteoArthritis in Denmark (GLA:D) osteoarthritis management programme. Analyses included 23 021 consecutive eligible adults with hip or knee osteoarthritis (mean (SD) age 65.0 (9.8) years, 71% female) treated by 657 therapists between October 2014 and February 2019. The primary outcome was ≥30% reduction in pain intensity on 0–100 visual analogue scale (VAS) at 3 months. Therapist effects were estimated as the variance partition coefficient (intraclass correlation coefficient (ICC)) from two-level random intercept logistic regression models before and after adjusting for patient-level case-mix factors and therapist-level characteristics (number of patients treated, days since therapist certification). Analyses were repeated for a range of secondary outcomes using multiply imputed data and complete-case analysis.
Results
52% of patients reported a ≥30% reduction in pain intensity on 0–100 VAS at 3 months. In the null model, the ICC was 0.007 (95% CI 0.005 to 0.009), which changed little after adjusting for patient-level and therapist-level covariates. Upper confidence limits for ICC estimates across all secondary outcomes in multiply imputed data and complete-case analyses were <0.03.
Conclusions
In a nationally implemented osteoarthritis management programme delivered by trained healthcare professionals, therapist effects made a minimal contribution to variation in patient outcomes.