Efficient engagement: opportunities for mobile methadone maintenance in geographically underserved areas.

In 2021 the Drug Enforcement Agency changed regulations to reduce barriers in the registration and operation of mobile methadone clinics for treating opioid use disorder in rural and underserved areas. How these routes might best be operated and how many clients might be served by mobile units are open questions. This work identifies candidate dispensing locations from mobile units in areas that do not have geographic access to a fixed clinic. Optimal routes for mobile methadone are identified by solving a mixed integer program that maximizes the number of clients without access to care that can be served by a mobile route. Ohio is used as a case study state to explore the efficiency of routes leaving from each methadone clinic in the state. The approach is generalized nationwide, and multi-vehicle routes are analyzed. Between 48 and 68 clients can be served by a single vehicle in a day (mean of 60) under default parameter assumptions across Ohio. Similarly, nationwide routes serve a mean of 47.5 clients per day. The second and third vehicle routes from a clinic provide access to an additional 95% and 93% of the clients of single vehicle routes, respectively. The number of servable clients on any route greatly differs based on geography. This work demonstrates the potential value of mobile methadone maintenance in reaching populations without geographic access to a fixed clinic. Additional policy and funding changes are needed to incentivize the operation of mobile methadone units for serving rural and unmet demand.