Osteoarthritis (OA) causes substantial pain and reduced health-related quality of life (HRQL). Although opioid analgesics are commonly used, the relative benefits of different opioids are poorly studied. Transdermal buprenorphine (TDB) offers an alternative to oral opioids for the treatment of moderate-to-severe chronic pain. This observational study of people with OA pain assessed satisfaction, HRQL and medication adherence.
Patients in the UK with self-reported knee and/or hip OA who had been receiving one or more of TDB, co-codamol (an oral paracetamol/codeine combination) and tramadol for at least 1 month completed an online or telephone questionnaire. Medication satisfaction scores, HRQL scores (Short-Form 36 [SF-36]), medication adherence (Morisky Medication Adherence Scale [MMAS™]), adverse events and treatment discontinuations were recorded. Linear and logistic regression models were used to compare the treatment effect of TDB with co-codamol or tramadol.
Overall, 966 patients met the inclusion criteria; 701 were taking only one of the target medications (TDB: 85; co-codamol: 373; tramadol: 243). The largest age group was 50-59 years and 76.0 % of patients were female. The TDB group was younger, with more male patients, therefore the statistical models were adjusted for age and sex. Medication satisfaction scores were significantly higher in the TDB group than the other two groups (TDB vs. co-codamol: 3.56, 95 % confidence interval [CI] 1.90-6.68, p < 0.0001; TDB vs. tramadol: 3.22, 95 % CI 1.67-6.20, p = 0.0005). Physical Component Summary scores for HRQL and mean adherence were also higher in the TDB group, while Mental Component Summary HRQL scores were similar across the three groups.
Patients with knee and/or hip OA pain treated with TDB were more satisfied and more adherent with their medication, and reported higher Physical Component Summary HRQL scores than those treated with co-codamol or tramadol, although demographic differences were observed between groups.