Can Exercise Therapy Lead to Clinically Meaningful Improvement in Hip Osteoarthritis Patients?
A new study addresses the challenge of determining whether treatments for hip osteoarthritis (OA) provide clinically meaningful benefit, not just statistically significant changes in outcome scores. While tools such as the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) effectively measure baseline severity and track changes over time, they do not clearly indicate whether a patient’s improvement is truly meaningful in clinical practice. The study was published in the Arthritis Care & Research journal by Yareni G. and colleagues.
Previous thresholds for meaningful benefit were largely based on surgical or drug therapies and may not apply well to physical or exercise-based interventions, given different patient expectations. This study establishes estimates for minimal important change (MIC) and minimal clinically important difference (MCID) for common pain and functional assessments following exercise therapy in hip OA, offering clearer guidance for evaluating real-world treatment benefit.
This study is considered a secondary data analysis of a study that was designed as a randomized controlled trial with 196 adults with hip OA. The participants were randomly assigned to one of two groups receiving a 9-month supervised program of structured exercises. Patient-reported data were collected at baseline, 3 months, and 9 months.
Pain severity was measured by the Numeric Rating Scale (NRS) and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain subscale. Physical function was measured by the WOMAC physical function subscale and the patient-specific functional scale (PSFS). Global rating of change of pain and physical function at 3 and 9 months was used as an anchor to measure improvement.
Key findings:
In a randomized trial with 196 adults with hip OA undergoing 9-month exercise interventions, MIC for NRS pain was 2.1 points at 3 months and 2.4 points at 9 months, while MCID was 2.0 points and 2.4 points, respectively.
MIC and MCID for WOMAC pain were 2.8 points and 2.8 points at 3 months, and 3.0 points and 3.0 points at 9 months.
MIC for WOMAC physical function was 8.7 points and 8.3 points, while MCID was 9.2 points and 8.3 points at 3 and 9 months, respectively. MIC for PSFS was -2.1 points and -2.0 points, while MCID was -3.5 points and -0.7 points at 3 and 9 months.
This research provides robust estimates of MIC and MCID values for pain and physical function outcomes in people with hip OA who receive exercise interventions from a physiotherapist. These values are useful in understanding the improvement in outcomes from the patient’s point of view and are crucial in the design of future exercise-based interventions in the treatment of hip OA.
Reference:
Guerrero, Y., Dobson, F., Venkatesha, V., Allison, K., Knox, G., Spiers, L., Haber, T., Hunter, D. J., & Hall, M. (2026). Minimal important change and minimal clinically important difference in pain and function with exercise in hip osteoarthritis. Arthritis Care & Research. https://doi.org/10.1002/acr.80029
