Comparing changes in health outcomes among patients with osteoarthritis participating at the GLA:D® Program and the Osteoarthritis Initiative.

To evaluate the impact of exercise therapy and education on PA, quality of life (QoL), and pain in a real-world setting over one year, we compare the changes in these outcomes between participants of the GLA:D® program to participants of the Osteoarthritis Initiative (OAI), who did not receive any specific treatment.

We included patients with knee OA from the GLA:D® registry (n=7,603) and the OAI (n=1,156). PA was measured using the UCLA PA scale for GLA:D® participants and the PA Scale for the Elderly (PASE) for OAI participants. To allow comparison, we mapped the PASE outcomes to fit the distribution of the UCLA scale of GLA:D® participants. QoL was assessed using the KOOS QoL scale (0 low to 100 high) and pain intensity was measured on a Visual Analog Scale (VAS), standardized to a 0-100 scale. Changes in outcomes were categorized as increased, maintained, or decreased levels. To ensure comparability between GLA:D® and OAI participants, we used entropy balancing and considered the covariates of age, gender, BMI, depression, employment status, and values of our outcomes at baseline.

After one year, 41% of GLA:D® participants increased their PA, compared to 38% in the balanced OAI group. QoL increased by at least ≥10 points in 48% of GLA:D® participants and in 40% of the balanced OAI group. Pain intensity decreased by a clinical relevance of ≥20 points in 40% of GLA:D® participants, compared to 27% in the balanced OAI group. Chi-squared tests showed significant differences between the treatment (GLA:D®) and balanced control (OAI) groups for pain intensity (χ² = 258.21, p-value 0.001), QoL (χ² = 33.03, Degrees of freedom = 2, p-value 0.001), and PA (χ² = 8.93, Degrees of Freedom = 2, p-value= 0.0115), indicating relevant associations between group assignment and these outcomes.

This study demonstrates that the positive changes in PA, QoL, and pain reduction, experienced by participants of the GLA:D® education and exercise program over one year are above the normal fluctuations typically observed in patients with OA.

The findings underpin that interventions like the GLA:D® program are beneficial in managing OA symptoms and improvements are not only due to normal fluctuation. This highlights the opportunities to improve PA, and QoL and decrease pain in patients with OA with a structured exercise therapy program. Further research is needed to explore these improvements' long-term sustainability and applicability to broader populations.