If You Want Patients with Knee Osteoarthritis to Exercise, Tell Them about NSAIDs

Objective: Exercise is an important adjunctive treatment for knee osteoarthritis (OA); however, it is underutilized, in part because of the known difficulties related to initiating and adhering to exercise programs. Although there are ample data documenting the latter, patient preferences for exercise in comparison with other options have not been examined. Methods: Participants were recruited as part of an intervention trial to improve decision making in knee OA. Patients with knee pain on most days of the preceding month completed an Adaptive Conjoint Analysis interactive computer survey designed to elicit patient preferences for a cream (capsaicin), oral medications (paracetamol [acetaminophen] and NSAIDs), intra-articular injections (up to four times per year), and exercise (low-impact aerobic exercise and/or strength training three times per week). Preferences were determined on the basis of individual respondent’s trade-offs between route of administration, probability of having less pain, probability of improved strength and endurance, risk of dyspepsia, and risk of ulcer. Preferences were calculated as ‘shares’ that sum to 100. Results: Ninety subjects completed the computer tool; mean age ± SD was 68 ± 9 (range 53–87) years. Patients preferred exercise over other treatment options whether intra-articular injections and NSAIDs were described as being 20% or 50% more effective at decreasing symptoms than other options. The relative importance assigned to treatment benefits and risks were 32.59% and 41.89%, respectively. Patient demographic characteristics were not related to preferences; however, patients with more self-reported knee pain were less likely to prefer exercise than their counterparts (r=−0.3, p=0.004). Conclusions: In this study, patients preferred exercise over pharmacological options for treatment of knee OA. Preferences were driven by patients’ unwillingness to accept the risk of adverse effects. Our findings also suggest that subjects with greater knee pain may be more reluctant to exercise than their counterparts. Presentation of exercise in the context of other available therapies might increase patient willingness to try exercising by making the trade-offs between exercise and medications more apparent. Copyright Adis Data Information BV 2008