Cost-Effectiveness of Treating Early to Moderate Stage Knee Osteoarthritis with Intra-articular Hyaluronic Acid Compared to Conservative Interventions.

INTRODUCTION

Evidence has demonstrated greater benefit of intra-articular hyaluronic acid (IA-HA) within earlier stages of knee osteoarthritis (OA) rather than waiting for patients to have progressed to later stages of disease progression. High molecular weight (HMW) HA has also been shown to be more effective than low molecular weight (LMW) HA products in mild to moderate knee OA, providing an important distinction to make within the class of IA-HA therapies. The purpose of this study is to evaluate the cost-effectiveness of treating patients with knee OA with HMW HA compared to LMW and conservative treatment, while taking into account disease stage.

METHODS

Decision analytic models were created for early/moderate, as well as late stage knee OA. Models for late stage knee OA were created by assuming a range of response rates to IA-HA treatments from 10% to 50%. These models included conservative treatment using physical therapy/exercise, braces/orthosis, and medications such as non-steroidal anti-inflammatory drugs (NSAIDs) and analgesics. The models compared the cost per quality adjusted life year (QALY) gained for these treatments to the use of either LMW or HMW HA. Incremental cost-effectiveness ratios (ICERs) were calculated for each treatment in relation to HMW HA.

RESULTS

When evaluating treatment in early to moderate knee OA, HMW HA was dominant over LMW HA and physical therapy/exercise, as it was less expensive and provided greater benefit. HMW HA was cost-effective versus braces/orthosis and NSAID/analgesic medications based on a willingness to pay threshold of $50,000. In the model of 50% response rate to IA-HA for late stage OA, HMW HA remained cost-effective in comparison to physical therapy/exercise and braces/orthosis at a willingness to pay threshold of $50,000; but not NSAID/analgesic medications. In the worst-case scenario of a 10% responder rate to IA-HA, HMW HA was no longer cost-effective in any circumstance.

CONCLUSION

IA-HA, particularly HMW formulations, demonstrate cost-effectiveness when compared to conservative treatment options and LMW HA in patients with early/mid stage knee OA. The cost-effectiveness of HMW HA in patients with later stage knee OA was not as apparent, particularly because of the uncertainty in the proportion of patients with late stage OA who have a meaningful improvement after receiving IA-HA. This cost-effectiveness finding supports the use of IA-HA in patients with early and moderate knee OA, as the benefits of IA-HA are apparent within the patient population with mild to moderate knee OA. The findings of this study suggest that there is a potential cost savings benefit as a result of utilizing HMW HA in earlier stages of knee OA as opposed to later stages.

FUNDING

Ferring Pharmaceuticals Inc.