Retention of Patients with OUD who use Methamphetamine after Instituting Low-Threshold Care in a Rural Alaskan OBOT

Introduction
Methamphetamine overdoses tripled in Alaska between 2015-2019, and the escalating use of methamphetamine by patients with OUD increases overdose risk. Buprenorphine therapy reduces mortality; but patient who use methamphetamine have lower retention in treatment in OBOT programs. Low-threshold OBOT programs have shown promise in increasing retention of high-risk patients, but few studies examine the implementation of low-threshold care in rural populations. Our rural Alaska clinic cares for under-served remote villages and Alaska native populations and is 200 miles from the nearest OTP. We recently added low-threshold care to our OBOT program, and we have performed a retrospective analysis to see if retention of patients with OUD who use methamphetamine increased after adding these services.
Methods
Our rural OBOT began offering low threshold services to our patients in the spring of 2018, which included offering XR monthly buprenorphine, same-day and walk-in appointments, co-located same-day behavioral health access, expanded peer support services, contingency management, active user outreach and harm reduction services. We reviewed EMR records for all patients admitted to our OBOT program during the periods of May 2016-April 2018 (n=74, treatment as usual-TAU), and May 2018-May 2020 (n=74, low-threshold) to identify patients with methamphetamine use. Patients were included if they met criteria for methamphetamine use disorder at time of admission or during treatment (16 patients from TUA group and 27 patients in low-threshold group). Patients were excluded from study if they demonstrated 6 months of continuous abstinence from methamphetamine use during their treatment. PDMP records were reviewed to determine the total number of weeks that each patient filled a prescription for buprenorphine, and compared length of treatment between the groups. We also examined subgroups of patients to determine if retention was associated with factors such as IV drug use, criminal justice/child services involvement, behavioral health engagement, housing security or formulation of buprenorphine (SL vs XR).
Results
The incidence of co-morbid amphetamine use disorder in our OBOT patients increased from 25% in the 2016-2018 group to 36% in the in the 2018-2020 group. Weeks of buprenorphine therapy was significantly increased in the low-threshold group vs the TAU group (22 weeks vs 9 weeks, P<0.05). The use of XR Buprenorphine in low-threshold group was associated with longer retention vs SL buprenorphine (32 vs 13 weeks, p<0.05). Peer support utilizers for both groups showed increased retention in treatment (24 vs 12 weeks, p<0.05). Other variables were not associated with significant differences in retention in either group.
Conclusion
The institution of low-threshold services in our rural Alaska OBOT was associated with significant increased duration of buprenorphine treatment in methamphetamine users with OUD. Among the variables examined, only peer support and the use of XR monthly buprenorphine was associated with significant increase in treatment duration. This data supports the use of low-threshold care in the rural setting, and the use of peer support and XR Buprenorphine in this population to increase retention. This study is limited by its small population size, and future studies should pool data from multiple rural OBOTs to increase statistical power