Assistant Professor Department of Epidemiology, University of California, Los Angeles, United States
Background: Medications for opioid use disorder (MOUD; buprenorphine/naloxone, extended-release naltrexone, methadone) are life-saving treatments that reduce risk of relapse and opioid overdose. Long-term adherence to MOUD is critical for therapeutic success, and race/ethnicity and chronic health conditions are essential to understanding MOUD adherence in real-world settings.
Objectives: To examine patterns of MOUD initiation, discontinuation, and indicators of treatment quality among patients with commercial insurance diagnosed with opioid use disorder in the United States.
Methods: We conducted a retrospective cohort study of patients diagnosed with opioid use disorder (OUD, based on ICD-10 codes) between 2016-2019 in the OptumLabs Data Warehouse. Patients were required to have 6 months of continuous enrollment with drug coverage prior to OUD diagnosis. Buprenorphine initiation was assessed in the 14 days after OUD diagnosis using outpatient pharmacy dispensing records. We examined patient demographic (age, sex, race/ethnicity, educational attainment) and clinical (mental health, substance use, infectious disease comorbidities) characteristics, and indicators of treatment quality (initial days supply, dose) during the baseline and treatment periods. Patients were followed until treatment discontinuation, disenrollment, or end of the study period on 12/31/2019. We used a weighted Kaplan-Meier estimator to examine 1-year risk of early treatment discontinuation.
Results: There were 42,817 patients diagnosed with opioid use disorder between 2016-2019. Patients were mostly non-Hispanic White (58%) and over half were 55 years or older. Approximately one-third of patients had anxiety (34%), depression (31%), and Hepatitis C (29%). Less than 10% of patients initiated MOUD within 14 days of OUD diagnosis; the most common MOUD was buprenorphine. Compared to White patients, Hispanic patients were less likely to initiate MOUD. Among patients initiating buprenorphine, Hispanic patients had the shortest initial days supply and lowest initial dose. Compared to White patients, Hispanic patients had higher 1-year risk of treatment discontinuation. No other race/ethnicities had differences in treatment duration or indicators of quality. Patients with anxiety were also less likely to initiate pharmacotherapy and had higher rates of treatment discontinuation than patients without mental health comorbidities.
Conclusions: Hispanic patients and patients with anxiety were less likely to initiate buprenorphine and had higher rates of early discontinuation than White patients and patients without mental health comorbidities. These differences highlight the need to pinpoint mechanisms to target interventions to equitably increase adherence to MOUD.
