Rationale, design and methods of the Cul-CM study: a protocol for cultural adaptation of contingency management in...

Stimulant use disorder is a growing contributor to drug poisoning and mortality in the USA, with disproportionate impact on black communities driven by stimulant-opioid polysubstance use and other structural barriers to treatment. Contingency management (CM) is the most effective evidence-based treatment for stimulant use disorder but remains poorly implemented especially in minoritised communities. Cultural adaptation represents a promising implementation strategy to improve acceptability, engagement and equity of CM while maintaining fidelity to core evidence-based programming.

The Cultural Adaptation of Contingency Management (Cul-CM) study is a multiphase, mixed-methods study designed to culturally adapt CM for black adults with stimulant use disorder and evaluate its preliminary outcomes in a pilot randomised controlled trial (RCT), guided by the PEN-3 cultural model and the ADAPT-ITT framework. Phase I consists of an assessment of clinician beliefs about CM implementation using the Extended Contingency Management Beliefs Questionnaire (CMBQ-CA+, with an exploratory Cultural Adaptation subscale) and a scoping review of CM adaptation for substance use disorder. Phase II employs PEN-3-informed individual interviews and focus groups to identify culturally salient determinants of CM uptake and engagement. Findings from Phases I and II, in addition to iterative expert and community advisory board reviews and feedback, will inform the development of a culturally adapted CM (CACM) protocol, which retains core effectiveness elements and modifies peripheral delivery elements of CM. Finally, the Phase III consists of a three-arm pilot RCT (n=60) comparing the CACM, standard CM and treatment as usual following a 1 week lead-in (priming) phase. Primary outcomes include stimulant abstinence and longest duration of continuous abstinence. Secondary outcomes include treatment acceptability, satisfaction, feasibility and retention. Cul-CM operationalises cultural adaptation as a systematic, theory-driven strategy to improve CM outcomes in adults with stimulant use disorder and promote equitable uptake in community treatment settings. Cul-CM represents a replicable framework for culturally adapting CM to ensure equitable access, engagement and improve outcomes.

Ethical approval was obtained from the Yale University Institutional Review Board. All participants will provide written informed consent. Study findings will be disseminated through peer-reviewed publications, scientific conferences and community-engaged channels to inform culturally responsive approaches to CM for stimulant use disorder.

NCT07443332.