Impact of Hyaluronic Acid Injections on Utilization of Pain Management Medications

Objectives: Little evidence has been available, from real-world clinical practice, on how the use of pharmacotherapy with pain medications changes in patients who begin using hyaluronic acid (HA) injections. We aimed to examine the impact of the initiation of HA injections on the utilization patterns of pain management modalities in patients with knee osteoarthritis (OA). Study Design: Retrospective pre-post design utilizing Truven Marketscan Commercial Claims and Encounters data from 2004 to 2011. Methods: The first HA injections received by patients aged between 18 and 64 years during the study period were identified from the data. Utilizations of 3 pharmacotherapies commonly used in the treatment of knee OA-nonsteroidal anti-inflammatory drugs (NSAIDs), corticosteroid injections, and opioids-in the 6-month pre- and post periods were assessed. These were measured as an average number of prescriptions per patient, and as proportions of patients using at least 1 of these agents. The independent variable in the study was a use of HA injection. Paired sample t test and McNemar's test were used to assess pre-post changes. Results: There were statistically significant decreases in the utilization of NSAIDs and in steroid prescriptions, along with a significant reduction in the proportion of patients filling these prescriptions during the post period (P<.001). In addition, the number of patients getting any opioid prescriptions reduced significantly during the post period (P<.001). Conclusions: The study results suggest that HA treatment may help reduce the use of other pain medications such as steroids, NSAIDs, and opioids.