Intra articular hyaluronic acid in the management of knee osteoarthritis: Pharmaco-economic study from the perspective of the national health insurance system.

INTRODUCTION: Pharmaco-economic data on the management of knee osteoarthritis (OA) with intra articular hyaluronic acid (IA HA) viscosupplementation is limited. We contrasted IA HA with non-steroidal anti-inflammatory drugs (NSAIDs).

METHODS: Observational, prospective and multicenter study comparing treatments of knee OA costs and efficacy with either NSAIDs alone, or hyaluronic acid (Arthrum H 2%®), during a 6-month follow-up period. The investigators were pharmacists who recorded data on disease, drug consumption and healthcare circuit. Retrospectively, the 6-month period preceding inclusion was also studied, to ensure the comparability of groups.

RESULTS: 199 patients were analyzed in a NSAIDs group and 202 in an IA HA group. Any of the WOMAC sub-scores and the EQ-5D Quality of Life index were significantly improved in the IA HA group (p<0.0001) at 3 and 6 months. Clinical results were therefore in favor of the IA HA group. The total drug expenses per 6-month period were comparable before and after inclusion, €96 and €98 for NSAIDs group vs €94 and €101 for IA HA group, which indicates no evidence of additional cost from IA HA. For the active part of the population, the incidence of sick leave was lower in the IA HA group, indicating a better maintenance of patient activity. The overall expense on 12 months (6 months before and 6 months after inclusion) for the national health insurance system was comparable for NSAIDs and IA HA groups: €528 and €526, respectively. The number of patients taking NSAIDs significantly decreased in IA HA group (from 100% at inclusion to 66% at 1-3 months and 44% at 4-6 months), but remained unchanged (100%) during the follow-up period, in NSAIDs group.

CONCLUSION: Treatment with IA HA did not generate additional cost for the national health insurance and was associated with a functional improvement of knee osteoarthritis and Quality of Life. The cost-utility analysis was in favor of IA HA, with a gain of QALY equivalent to half a month, after the 6-month follow-up period comparing both treatments. The NSAIDs consumption was decreased in the IA HA group, resulting in an improved estimated benefit/risk ratio.