(68) Mobilizing Contingency Management for Stimulant Use Disorder in the Street Medicine Setting

Background & Introduction: Contingency management (CM) is an evidence-based, substance use treatment intervention that involves incentivizing abstinence from a behavior, often using monetary rewards. Research has shown that CM is among the most effective known treatments for stimulant use disorder and has also been found to have a positive impact on co-occurring psychiatric symptoms 1,2

While CM has been shown to be effective, barriers to access for the unhoused include lack of insurance, transportation, and other resources that make consistent attendance difficult.

The “Recovery Incentives Program” is a 16-24 week mobile Contingency Management (mCM) program, integrated within an existing multidisciplinary street medicine model (Healthcare in Action) operating in Southern California. Street medicine clinical providers refer candidates who meet criteria (i.e. adult with active StUD) to the internal program and dedicated staff review referrals for appropriateness before initiating programming. Weekly CM visits are conducted by program staff and urine drug screens are obtained. Participants receive escalating gift cards incentives for urine drug screens negative for stimulants such as amphetamine, methamphetamine, and cocaine.

This study seeks to evaluate patient perspectives regarding their experience with a novel, mCM program including their perception of self-efficacy and attitudes toward specific program components including staff, setting, and incentives.

Methods: This qualitative mixed-methods study was conducted following Institutional Review Board approval. Data were collected over a two-week period during routine mCM by a mobile street medicine team in the Inland Empire region of Southern California, including encampments, motels, and sober living settings. Fifteen participants were interviewed.

Adults (≥ 18 years old) who were enrolled in the mCM program at any point were eligible. Participants were recruited using convenience sampling from scheduled outreach encounters. Informed consent was obtained verbally, and participants were informed that participation would not affect their care or program involvement.

Semi-structured, in-person interviews were conducted by a single investigator, individually or in dyads, lasting approximately 5–40 minutes. Interviews included open- and closed-ended questions and verbally administered Likert-scale items developed by the study team and hosted in Qualtrics. Interviews were audio-recorded using de-identified recordings.

In the qualitative portion, transcripts from the audio recordings were analyzed. The investigator performed a post-hoc analysis to identify pertinent themes using Dedoose 10.0.59.

An inductive thematic analysis approach was used with iterative code refinement. Coding was conducted by the investigator with ongoing discussion and guidance from the principal investigator to refine themes. Descriptive statistics for Likert-scale responses were analyzed in Microsoft Excel.

Results: Fifteen participants (n=15) completed qualitative surveys and semi-structured interviews evaluating a mCM program for StUD. Participants had a median age of 50 years (IQR 8.5). 60% (n=9) identified as female and 40% (n=6) as male. 100% reported history of methamphetamine use. Inhalation was the most common route of administration among the study group (93%), followed by intranasal (33%) and intravenous routes (27%). Age of initiation was evenly distributed, with half (50%) initiating stimulant use before age 18.

27% (n=4) of participants were documented as unsheltered at the time of their enrollment in the mCM program. By the time of their interview, housing status had improved for 27% of participants, remained unchanged for 73%, and declined for 7%.

Program engagement was high within the study group; 73% of participants had completed more than 8 weeks of CM at the time of the interview, with a median participation duration of 9 weeks (IQR 11.5). The study group also had considerable experience with other treatment modalities. 93% of participants reported prior exposure to other treatment approaches for stimulant use, most commonly residential treatment such as detoxification and rehabilitation (100%), group therapy (36%), mutual support or 12-step programs (36%), individual counseling (29%), sober living (29%), and medications for addiction treatment (14%).

We also captured participant perspectives on how the mCM reduced barriers to treatment. The majority of the study group rated the mCM program as easier to enroll (67%) and maintain (81%) in than other treatment interventions they had experienced in the past. Recovery-related self-efficacy measures were also high; 80% (n =12) reported they felt more successful in reducing stimulant use within the mCM program than in other treatment programs they had experienced, and 86% (n=13) indicated that they were confident they would be able to continue their recovery beyond the program.

All participants (100%) agreed that it was “extremely important” to them that they were able to do CM visits in “their place of residence instead of needing to go to a hospital or clinic, that the mCM program was designed “specifically for people experiencing homelessness” and that the CM visits were “done by people [they] trust.”

Common themes extracted from semi-structured interview content as possible barriers to StUD treatment included (1) Unsheltered homelessness promoting continued stimulant use due to social pressure and need for increased alertness. (2) interpersonal conflict in prior treatment programs. (3) Prior treatment being court-ordered rather than voluntary.

Conclusion & Discussion: The primary barrier to treatment identified by participants was being unsheltered. Participants described relying on stimulants to remain awake in order to protect themselves from crime, as well as experiencing social pressure to use substances within unsheltered communities. The mCM program addressed this barrier by being embedded within a pre-existing multidisciplinary street medicine team that coordinated housing placement for many participants before or during enrollment.

The multidisciplinary care team was central to participants’ perceived success in recovery. Participants consistently cited trusting relationships with social workers and healthcare providers as major sources of motivation and accountability. Many reported that these relationships were more motivating than the monetary incentives themselves. Additional non-monetary benefits included increased access to medical and social services through more frequent encounters and the ability to produce documentation of negative urine drug screens for housing, employment, or legal purposes.

These established relationships also mitigated barriers related to interpersonal conflict and loss of autonomy commonly experienced in residential treatment settings. Participants valued remaining connected to family, partners, pets, and community. By pairing housing support with a flexible, ambulatory CM model, mCM preserved autonomy while minimizing treatment-disrupting conflict, likely contributing to high program adherence at three months (83%).

References: 1. Dutra L, Stathopoulou G, Basden SL, Leyro TM, Powers MB, Otto MW. A meta-analytic review of psychosocial interventions for substance use disorders. Am J Psychiatry. 2008;165(2):179-187. doi:10.1176/appi.ajp.2007.06111851

2. McDonell MG, Srebnik D, Angelo F, et al. Randomized controlled trial of contingency management for stimulant use in community mental health patients with serious mental illness. Am J Psychiatry. 2013;170(1):94-101. doi:10.1176/appi.ajp.2012.11121831

3. Assaf RD, Morris MD, Straus ER, Martinez P, Philbin MM, Kushel M. Illicit Substance Use and Treatment Access Among Adults Experiencing Homelessness. JAMA. 2025;333(14):1222-1231. doi:10.1001/jama.2024.27922