Opioid Use Following Total Hip Arthroplasty: Trends and Risk Factors for Prolonged Use.

Background: The purpose of this study is to answer the following questions: (1) What is the prevalence of opioid use prior to primary total hip arthroplasty (THA)? (2) What is the typical trend in opioid use following THA over the first post-operative year? (3) What are the risk factors for prolonged opioid use following primary THA?

Methods: Primary THA patients were identified in the Humana database from 2007 to 2015. Pre-operative and post-operative opioid use was measured by monthly prescription refill rates. Rates of opioid use were trended monthly for 1 year post-operatively and compared based on pre-operative opioid user (OU) status as well as other patient demographics and co-morbidities.

Results: In total, 37,393 THA patients were analyzed and 14,309 patients (38.2%) were pre-operative opioid users (OUs). Pre-operative opioid use was the strongest predictor for prolonged opioid use following THA, with non-opioid users filling significantly less opioid prescriptions than OUs at every time point analyzed. Younger age, female sex, and all other diagnoses analyzed were found to significantly increase the rate of opioid refilling following THA throughout the entire post-operative year.

Conclusion: Over one-third of THA patients use opioids within 3 months prior to THA and this percentage has increased 6% during the years included in this study. Pre-operative opioid use was most predictive of increased refills of opioids following THA. These data provide an important baseline for opioid use trends following THA that can be used for future comparison while identifying risk factors for prolonged use that will be helpful to prescribers as we all work to decrease opioid use, misuse, and abuse.