Do patients' treatment beliefs affect treatment choices in knee and hip osteoarthritis?

Background Patients9 beliefs about treatment modalities for knee/hip osteoarthritis (OA) might influence their treatment choices. The Theory of Planned Behavior predicts that patients9 beliefs, the norms and values of one9s social environment (subjective norm) and one9s perceived self-efficacy influence behaviour 1 . Moreover, symptom severity may influence treatment choices 2 . However, these relationships have not been studied yet in the context of treatment decision-making. Objectives To test whether treatment beliefs, subjective norm, perceived self-efficacy and symptom severity were associated with intended treatment choices in OA. Methods Patients with knee/hip OA who visited the Sint Maartenskliniek in 2015 and 2016 (N=700) were invited to fill out a booklet. The Treatment beliefs in OsteoArthritis questionnaire was used to assess positive and negative treatment beliefs regarding five treatment modalities: physical activities, pain medication, physiotherapy, injections and arthroplasty. Other measures were demographic and clinical variables, self-efficacy (ASES), and symptom severity (WOMAC). Associations between variables were assessed in three models (Figure 1): 1) whether treatment beliefs are associated with intended treatment choice (model 1); 2) whether treatment beliefs, subjective norm and perceived self-efficacy are associated with intended treatment choice (model 2); 3) whether treatment beliefs, subjective norm, perceived self-efficacy and symptom severity are associated with intended treatment choice (model 3). Path analyses were conducted to examine the hypothesized associations. Results 289 patients filled out the booklet. Model 2 had the highest explained variance for each of the treatment modalities (range 32–45%). Positive treatment beliefs and subjective norm were consistently associated with intended treatment choice across all treatment modalities. Negative treatment beliefs were associated with intended treatment choices for pain medication and arthroplasty. Perceived symptom severity was not related to intended treatment choices. No other associations were found. Conclusions This is the first study that found empirical support for the relationship between treatment beliefs and treatment choices. The findings suggest that positive beliefs about treatment modalities and the norms and values of one9s social environment are related to a specific treatment choice for knee/hip OA and should be addressed in the clinician9s consulting room. References Ajzen, I. (1991). The Theory of Planned Behavior. Organ Behav Hum Dec 50. 179–211. Rosemann (2007). Health service utilization patterns of primary care patients with osteoarthritis. BMC Health Serv Res 7: 167. Disclosure of Interest None declared