Patients' beliefs about treatment modalities for knee and hip osteoarthritis (OA) will underlie their treatment choices. Based on the Theory of Planned Behavior, it is hypothesized that patients' beliefs, subjective norm, and perceived behavioral control guide their treatment choices. Also, symptom severity and one's inherent tendency to approach or avoid situations are assumed to play a role. The objective of this study was to test whether these variables were associated with intended treatment choices in knee and hip OA.
Patients with knee and hip OA were randomly selected from hospital patient records. They completed the Treatment beliefs in OsteoArthritis questionnaire to assess positive and negative treatment beliefs regarding five treatment modalities: physical activities, pain medication, physiotherapy, injections, and arthroplasty. Other measures were intention, subjective norm, perceived behavioral control (ASES), symptom severity (WOMAC), and the person's general tendency to approach or avoid situations (RR/BIS scales). Three models were tested using path analyses to examine the hypothesized associations.
Participants were 289 patients. 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. Other associations were not significant.
This is the first study testing the Theory of Planned Behavior in the context of treatment choices in OA. Findings suggest that foremost positive beliefs about treatment modalities and the norms of one's social environment guide a specific treatment choice. Unexpectedly, symptom severity was not related to intended treatment choices.