OBJECTIVES To estimate the budget impact and the cost-effectiveness of viscosupplementation with SynviscOne®/Synvisc® alone compared with conventional support therapies in the treatment of knee and hip osteoarthritis in Italian setting.

METHODS : The model used was a Markov model with states for stages II – IV on the Kellgren-Lawrence scale, and then states for either total knee replacement or total hip replacement, the after-replacement period, and death. The model runs on six-month cycles.A five-year horizon was chosen with a 3.5% discount applied to both costs and utilities. Progression rate of patients through the K-L states and effectiveness were derived from literature. Direct costs were determined from perspective of the Italian National Health Service. A one-way sensitivity and probabilistic analyses were conducted for both comparisons.

RESULTS Monte Carlo simulations were performed for 1,000 patients for knee OA both SynviscOne®(1injection x6ml) and Synvisc®(3injection x2ml). The same simulation was conducted for hip OA with Synvisc®(1injection x2ml). Synvisc-One® and Synvisc®3x2 for knee OA were very likely to be cost-effective when compared to acetaminophen(ICER= €3,160.61 and €3,845.81,respectively) and NSAIDs (ICER= €7,440.07 and €10,229.83, respectively) as both ICERs are below €25,000. The hip OA treatment by Synvisc®1x2 was dominant compared to NSAIDs and very likely compared to acetaminophen (ICER= € 937.10). The results of the CEA were confirmed by one-way sensitivity and probabilistic analyses. The BIA for knee OA showed a raise of €99.99 and €122.49 per patient per year, respectively with SynviscOne® and Synvisc®3x2.Approximately €151.06 per patient per year, was shown in the BIA for hip OA treatment.

CONCLUSIONS Viscosupplementation decrease the consumption of medication and the drug-related adverse events, delay the prosthesization,leading to a reduction of the osteoarthritis economic burden on the National Health System. However, Real Word Evidence studies should be conducted in order to accurately estimate costs associated with both prosthetics and viscosupplementation.