BackgroundThe Veterans Health Administration (VHA) has made significant improvements in increasing prescribing of medication treatment for opioid use disorder (MOUD) and medication treatment for alcohol use disorder (MAUD); however, several barriers to treatment retention remain. In an effort to improve MOUD/MAUD retention, a Veterans Affairs (VA) facility established a pharmacist-led substance use disorder (SUD) transitions of care telephone clinic for patients discharged from an inpatient hospitalization on MOUD/MAUD, including buprenorphine/naloxone (BUP/NAL) and extended-release (ER) naltrexone injections. Pharmacists within the clinic assess aspects of treatment retention such as medication tolerability, perceived barriers to continuing treatment, status of current prescriptions, and appointment coordination. ObjectivesThe primary objective of this study was to evaluate the impact of a pharmacist-led SUD transitions of care telephone clinic on MOUD/MAUD retention following inpatient initiation in patients with opioid use disorder (OUD) and/or alcohol use disorder (AUD). Secondary objectives included subanalyses of clinic impact on MOUD/MAUD retention based on study medication or diagnoses, health care utilization, and characterization of pharmacist interventions. MethodsThe study identified patients for inclusion from inpatient units at a VA hospital. The study included patients if they were >18 years of age, had a diagnosis of AUD and/or OUD, and were initiated on ER naltrexone or BUP/NAL during admission and continued at discharge from August 1, 2018, to December 31, 2019. The study excluded patients if they declined clinic involvement, transferred facilities, moved beyond the VA catchment area, or were unable to be reached for initial contact after 3 telephone attempts. The intervention group included patients enrolled in the pharmacist-led SUD transitions of care telephone clinic, while the control group included patients initiated on MOUD/MAUD during admission who were eligible but not referred for clinic enrollment. Results/conclusionsThe study identified a total of 150 patients for inclusion (n = 54 intervention group; n = 96 control group). The study observed a statistically significant difference for the primary endpoint of combined 1- and 3-month MOUD/MAUD retention rates as measured by a continuous, multiple-interval measure of medication acquisition (CMA) of ER naltrexone and BUP/NAL for the intervention group vs. control group (1-month: 77.3% vs. 56.8%, p = 0.004; 3-month: 71.4% vs. 48%, p = 0.0002). When analyzed by study medication, we also observed a statistically significant improvement in continuous use of ER naltrexone for those enrolled in the clinic (1-month: 71.4% vs. 45.9%, p = 0.01; 3-month: 66.7% vs. 34.4%, p = 0.0003). The study did not observe any statistically significant improvements for BUP/NAL (1-month: 87.1% vs. 75.8%, p = 0.13; 3-month: 79.4% vs. 68.5%, p = 0.24) or establishment with a BUP/NAL clinic (90.5% vs. 80% patients established, p = 0.46). Likewise, the study did not observe any statistically significant differences for combined emergency department (ED) visits (1-month: 24.1% vs.17.1% patients with ED visit, p = 0.40; 3-month: 31.5% vs. 29.2% patients with ED visit, p = 0.85) or hospitalizations (1-month: 9.3% vs. 14.6% re-hospitalization, p = 0.45; 3-month: 14.8% vs. 26% re-hospitalization, p = 0.15) for those in the intervention group vs. the control group. Overall, the study observed statistically and clinically significant improvements in MOUD/MAUD retention rates for patients enrolled in a pharmacist-led SUD transitions of care telephone clinic.