Cost-Effectiveness of Chondroitin Sulphate (with or without Glucosamine) Prescription in the Treatment of Knee Osteoarthritis Compared to NSAIDs and COXIBs

Background: Chondroitin sulfate, alone or associated with glucosamine (CS/CS+GLU), is an effective knee osteoarthritis (KOA) treatment, with fewer adverse effects (AEs) than non-steroidal anti-inflammatory drugs (NSAIDs) and cyclooxygenase 2 inhibitors (COXIBs). Purpose: To estimate the CS/CS+GLU cost-effectiveness versus NSAIDs/COXIBs, due to the avoidance of mild-moderate or severe gastrointestinal AEs (GIAE), ischemic heart disease (IHD), acute kidney insufficiency (AKI), chronic kidney failure (CKF) and ischemic stroke (IS) from the Spanish National Health System (NHS) perspective. Methods: Two analyses were considered: 1) savings to the NHS from current CS/CS+GLU treatment; and 2) maximum savings that could be achieved by the NHS if all patients with KOA currently treated with NSAIDs/COXIB would be switched to CS/CS+GLU. AEs frequency, associated utilities loss and managing cost were obtained from medical literature and Spanish sources. A probabilistic model (second-order Monte Carlo simulation) was carried out for a 3-year time horizon. Treatment duration: 180 days (base case); 90 and 240 days (sensitivity analysis). Results: First analysis: 45,087 mild-moderate GIAE, 3,217 severe GIAE, 211 IHD, 1,087 AKI, 746 CKF and 3,359 IS, would be avoided with CS/CS+GLU. Discounting drugs cost, the three-year savings would be 57.1 million euros (savings probability: 80.7%). The savings per patient treated with CS/CS+GLU would amount to € 38.02 (95% CI 14.06; € 75.69), with a mean gain of 0.0023 (95% CI 0.0018– 0.0027) QALY. The probability that CS/CS+GLU treatment was dominant (lower costs and QALY gain) or cost-effective (cost per QALY gained less than € 25,000) was 80.7% and 98.1%, respectively. In the second analysis, savings for the NHS would amount to 387 million euros, with the CS/CS+GLU-only option being dominant and cost-effective in 100% of the analyses. Conclusion: The improved tolerability of CS/CS+GLU versus NSAIDs/COXIBs is expected to prevent thousands of AEs and generate considerable savings for the NHS, making it cost-effective treatment. Keywords: knee osteoarthritis, chondroitin sulfate, glucosamine, cost-effectiveness, budgetary impact, health impact