Implementing Three-Day Methadone in a Low-Threshold Bridge Clinic: Impact of OTP Referral Pathways on Treatment Retention

Background Methadone is effective for treating opioid use disorder (OUD) but must be dispensed through federally regulated opioid treatment programs (OTPs). Geographic scarcity, waitlists, and limited intake schedules can delay OTP enrollment, causing patients to miss treatment opportunities. Regulations permit non-OTP practitioners to provide up to three days of methadone to bridge patients to OTP enrollment. This study evaluates the rates of linkage to and early retention in an OTP after initiation of three-day methadone at a Bridge Clinic. Methods We conducted a retrospective case series of all patients who initiated methadone under the three-day rule at the San Francisco General Hospital Bridge Clinic between June 2024 and July 2025. The hospital also houses an OTP in the same building, which referred patients who were unable to complete intake. Outcomes included linkage to OTP care within seven days and retention at 30 days. Safety monitoring included review of all urine drug screens with either positive for methadone or negative for non-prescribed opioids, emergency department visits, hospitalizations within seven days, and Medical Examiner overdose reports. Multivariable logistic regression examined the association between OTP referral and 30-day retention. Results Among 166 unique patients who received at least one dose of three-day methadone, 63% percent (104/166) linked to an OTP within seven days. Among patients who linked within seven days, 62% (64/104) were retained at 30 days. Referral from OTP to Bridge clinic was associated with 3.1-fold increased odds of 30-day retention. No methadone-related emergency department visits, hospitalizations, or deaths within 30 days of receipt of methadone were observed. Medical record review of unexpected urine drug screen results revealed that one patient was already enrolled in methadone treatment prior to receiving a dose. Conclusions Initiating methadone in a low-threshold Bridge Clinic is feasible for engaging patients in OTP care. Referral from OTP to Bridge Clinic was associated with improved treatment retention. Trial registration: not applicable