Buprenorphine-Naloxone vs. Methadone for Opioid Use Disorder in Primary Care: 12-Month Retention and Opioid-Negative Urine Toxicology in a Cohort of 1,842 Patients

This study investigates 12-month treatment retention and opioid-negative urine toxicology comparison between buprenorphine-naloxone and methadone for opioid use disorder in a primary care setting within the context of addiction medicine and primary care research, an area of growing scientific importance given its implications for primary care opioid treatment program design, treatment matching protocols, and equity-focused MOUD access expansion policy. Using retrospective cohort study with inverse probability of treatment weighting propensity adjustment comparing 12-month retention and urine toxicology across treatment modalities, we examine buprenorphine-naloxone partial agonist ceiling effect limiting overdose risk and enabling office-based dispensing, while methadone full agonist providing superior suppression of high-tolerance opioid use but requiring daily clinic attendance in 1,842 OUD patients (924 buprenorphine-naloxone, 918 methadone) initiated in primary care integration between 2016-2019 with 12-month follow-up through EHR linkage drawn from 14 primary care clinics with integrated addiction medicine services at Northshore Health System, Chicago. Results indicate that IPTW-adjusted 12-month retention is 58.4% for BUP-NX versus 62.4% for methadone (p=0.048); opioid-negative UDS rate is 64.2% (BUP-NX) versus 74.2% (methadone) at month 12; overdose rate 2.4 vs. 1.8 per 100 person-years respectively (p = 0.048), with Retention: 58.4% BUP-NX vs. 62.4% methadone; UDS negative: 64.2% vs. 74.2% as the primary quantitative benchmark. Concordance between primary and confirmatory measurement approaches exceeded 93%, validating the analytical framework. These findings contribute empirically to addiction medicine and primary care research and carry actionable implications for the design of programs and policies targeting primary care opioid treatment program design, treatment matching protocols, and equity-focused MOUD access expansion policy.