Contingency Management for Stimulant-Opioid Co-Use: A Systematic Review and Meta-Analysis

OBJECTIVE: We conducted a meta-analysis (PROSPERO CRD420251000204) examining treatment outcomes associated with contingency management for individuals with stimulant-opioid co-use. METHODS: We searched Cochrane Library, Embase, PubMed, PsycINFO, and Web of Science through March 2026. Randomized controlled trials evaluating contingency management among individuals with past-year stimulant-opioid co-use were eligible. Outcomes included the longest duration of continuous, simultaneous abstinence from stimulants and opioids during treatment, the percentage of combined stimulant-opioid-negative urine toxicology samples, and treatment retention. Data were extracted following PRISMA guidelines, and random-effects meta-analyses were performed. RESULTS: Twenty-six trials (N=2356) were included. Across studies, cocaine was the stimulant of interest and heroin the primary opioid; fentanyl exposure was not reported in any trial. Contingency management significantly increased the longest duration of continuous abstinence from concurrent stimulant and opioid use compared with control conditions (mean difference=1.42 wk, 95% CI: 0.77-2.08; I²=50%). Participants receiving contingency management were more likely to submit combined stimulant-opioid-negative urine samples (odds ratio=2.46, 95% CI: 1.96-3.10; I2=0%). Overall treatment retention did not differ between groups, though subgroup analyses suggested improved retention among participants not receiving medication for opioid use disorder. CONCLUSIONS: Contingency management improves abstinence outcomes among individuals with stimulant-opioid co-use across treatment settings. The absence of fentanyl-specific data highlights an urgent need for research addressing treatment strategies in the context of the evolving synthetic opioid epidemic.