Tailored Exercise Improves Knee Osteoarthritis Symptoms

Kelli Allen, PhD

A self-directed, stepped exercise program that was found more likely to provide modest improvement of knee osteoarthritis symptoms than an education-based approach could benefit patients with limited access to a physical therapist.

Kelli Allen, PhD, Thurston Arthritis Research Center, University of North Carolina at Chapel Hill and Center of Innovation to Accelerate Discovery and Practice Transformation (ADAPT), Durham VA Health Care System, and colleagues conducted a randomized controlled trial involving a novel stepped exercise program for veterans with knee osteoarthritis (STEP-KOA) to assess its effectiveness, and potential to extend limited physical therapy resources.

“Efficiency of care delivery was one primary drive of the model,” Allen told HCPLive. “That is one advantage of stepped care models in general, and it can be important for health systems.”

Stepped care models such as this also hold benefit for patients, Allen said: intervention can be tailored to the person’s improvement in previous steps, lowering the demand for time and resources dedicated to the program.

The trial was conducted at 2 VA sites with 345 veterans with diagnosed knee osteoarthritis and self-reported joint pain of ≥3 on a scale of 10 during the 2 weeks prior to enrollment. Participants were randomized 2:1 to the STEP-KOA intervention or to receive educational materials on osteoarthritis and on managing symptoms.

The primary outcome was reduction in WOMAC (Western Ontario and McMaster Universities Osteoarthritis Index) measure of pain, stiffness, and function. Secondary outcome measures of physical functioning included a 30-second chair stand test and 40-meter fast-paced walk. The estimated baseline WOMAC score for the full sample was 47.5.

Criteria for response correspond to the OMERACT-OARSI (Outcome Measures in Rheumatology-Osteoarthritis Research Society International). Response was deemed clinically significant if there was at least 50% improvement in pain or function and absolute change of ≥20; or at least 2 of the following: at least 20% improvement in pain and absolute change of ≥10, at least 20% improvement in function and absolute change of ≥10, or Patient Global Impression of Improvement score of "better" or "much better.”

Step 1 of the STEP-KOA began with access to an internet-based exercise program for knee osteoarthritis.Participants not meeting criteria for response in 3 months could progress to step 2, a biweekly telephone coaching session that addresses barriers to physical activity. If response remained inadequate after an additional 3 months, participants could progress to step 3, with in-person physical therapy sessions.

The investigators reported that most (65%) of participants had to proceed to step 2, and 35% went on to step 3.At the nine-month follow-up, the estimated mean reduction was -5.5 points (95% CI, -7.7 to -3.2) in the STEP group and -1.4 (95% CI, -1.6 to -4.3) in the arthritis education control group.

"We acknowledge that this between-group difference is on the lower end of clinical relevant improvement for WOMAC scores," Allen and colleagues wrote.

Allen considered whether the 65% of participants requiring progression to step 2 suggests that initial treatment should combine measures from step 1 and 2, noting that the study was not designed to evaluate the more comprehensive initial intervention.

"However, I think that combining step 1 and 2 would generally be a reasonable approach based on prior research in this area," she said.

Allen and colleagues indicate that further work is needed to identify strategies to improve the effectiveness of, and adherence to exercise-based interventions, and to maintain improvements in symptoms.

Allen commented that her group will also further evaluate this study data.

"We do plan to conduct some follow-up analyses to understand which patient characteristics predicted greater degree of improvement with the STEP-KOA program," she said.

The study, “Stepped Exercise Program for Patients with Knee Osteoarthritis,” was published online in Annals of Internal Medicine.