Prognostic Factors for Health Outcomes After Exercise Therapy and Education in Individuals With Knee and Hip Osteoarthritis With or Without Comorbidities: a study of 37,576 patients treated in primary care

OBJECTIVE: To identify prognostic factors for health outcomes following an 8-week supervised exercise therapy and education program for individuals with knee and hip osteoarthritis (OA) alone or with concomitant hypertension, heart or respiratory disease, diabetes mellitus, or depression.

METHODS: We included individuals with knee and/or hip OA from the Good Life With OsteoArthritis in Denmark (GLA:D) program. GLA:D consists of 2 patient education sessions and 12 supervised exercise therapy sessions. Before GLA:D, participants self-reported any comorbidities and were categorized into 8 comorbidity groups. Twenty-one potential prognostic factors (demographic information, clinical data, and performance-based physical function) gathered from participants and clinicians before the program were included. Outcomes were physical function using the 40-meter Fast-Paced Walk Test (FPWT), health-related quality of life using the 5-level EuroQol 5-domain (EQ-5D-5L) index score, and pain intensity using a visual analog scale (VAS; range 0-100) assessed before and immediately after the GLA:D program. Within each comorbidity group, associations of prognostic factors with outcomes were estimated using multivariable linear regression.

RESULTS: Data from 35,496 (40-meter FPWT) and 37,576 (EQ-5D-5L and VAS) participants were included in the analyses. Clinically relevant associations were demonstrated between age, self-efficacy, self-rated health, and pain intensity and change in 40-meter FPWT, EQ-5D-5L, or VAS scores across comorbidity groups. Furthermore, anxiety, education, physical function, and smoking were associated with outcomes among subgroups having depression or diabetes mellitus in addition to OA.

CONCLUSION: Age, self-efficacy, self-rated health, and pain intensity may be prognostic of change in health outcomes following an 8-week exercise therapy and patient education program for individuals with OA, irrespective of comorbidities.