Abstract
BACKGROUND: With the rising costs for knee arthroplasty, therapies that allow patients to avoid or delay surgery following knee osteoarthritis (KOA) may help in reducing overall health care costs. Multiple intraarticular hyaluronic acid (HA) products are available on the market, varying by formulation, molecular weight, and number of injections, but clinical and economic benefits may differ by product. OBJECTIVES: To evaluate the all-cause and KOA-related health care resource utilization (HCRU) and costs among newly diagnosed patients with KOA treated with multi-injection HA. METHODS: A retrospective cohort study using a large commercial claims database (Merative MarketScan database) to identify patients with KOA treated with high molecular weight (HMW) (n = 11,200), medium molecular weight (MMW) (n = 10,225), or low molecular weight (LMW) HAs (n = 8,473) between 2016 and 2019. KOA-related and all-cause HCRU and costs were compared within 12 months after the index HA treatment date. The association between outcomes and HA treatments was evaluated using a doubly robust method to adjust for confounding factors. HCRU and costs among the propensity score-weighted HA groups were compared using generalized linear models. RESULTS: HMW HA patients were found to have lower adjusted KOA-related medical costs by $265.37 (P < 0.001) and pharmacy costs by $19.90 (P < 0.001) compared with LMW HA patients, as well as lower all-cause total medical costs by $130.42 (P = 0.013) and pharmacy costs by $63.33 (P < 0.001). HMW HA patients also had a lower adjusted KOA-related medical cost by $205.74 (P < 0.001) and pharmacy cost by $14.39 (P < 0.001) compared with MMW HA patients, as well as lower all-cause medical by $1,195.66 (P < 0.001) and pharmacy by $196.99 (P < 0.001). Three-injection treatment patients (HMW HA, 84%; MMW HA, 82%) had high completion rate, compared with the 5-injection treatment cohort (LMW HA, 48%). CONCLUSIONS: HMW HA patients had statistically significantly lower adjusted all-cause and KOA-related medical and pharmacy costs at 1 year follow-up compared with MMW HA and LMW HA patients. It is unclear if this is related to differences in molecular weight or specific mechanism of actions.