Economic evaluation of controlled-release oxycodone vs oxycodone-acetaminophen for osteoarthritis pain of the hip or knee.

OBJECTIVE: To examine, in routine practice, the effectiveness and cost-effectiveness of oxycodone (OxyContin) compared with standard therapy for osteoarthritis pain. STUDY DESIGN: Open-label active-controlled randomized naturalistic 4-month study of oxycodone vs a combination of oxycodone-acetaminophen (Percocet). METHODS: Outcomes and health resource utilization data were collected by telephone interview. Effectiveness was measured among 485 patients as the proportion having at least 20% improvement from baseline in the Western Ontario and McMaster Universities Osteoarthritis Index pain score. Quality-adjusted life-years (QALYs) were calculated from the Health Utilities Index 3 score. Cost-effectiveness was measured as cost per patient improved and the QALYs gained, using generic oxycodone-acetaminophen in the base case for the healthcare and societal perspectives. Uncertainty was evaluated using multiple 1-way sensitivity analyses and cost-effectiveness acceptability curves. RESULTS: Improvement occurred in 62.2% of patients with oxycodone and in 45.9% of patients with oxycodone-acetaminophen (P < .001). After adjustment for baseline differences, 0.0105 QALYs were gained with oxycodone compared with oxycodone-acetaminophen (P = .17). The mean societal costs per patient during 4 months were 7379 US dollars and 7528 US dollars for oxycodone and oxycodone-acetaminophen, respectively (P = .33). Oxycodone was more effective and less costly than oxycodone-acetaminophen based on the societal perspective (including costs associated with time lost). Based on the healthcare perspective (excluding costs associated with time lost), the cost-effectiveness of oxycodone was 4883 US dollars per patient improved and 75,810 US dollars per QALY gained. The base-case results were robust. CONCLUSIONS: From the societal perspective, oxycodone was more effective and less costly than oxycodone-acetaminophen. From the healthcare perspective, oxycodone (compared with generic oxycodone-acetaminophen) fell within the acceptable range of cost-effectiveness between 50,000 US dollars and 100,000 US dollars per QALY gained.