Sex effects in cocaine-using methadone patients randomized to contingency management interventions

Contingency management (CM) is an effective treatment for promoting cocaine abstinence in patients receiving methadone maintenance. However, few studies have examined the effect of sex on treatment outcomes in this population. This study evaluated the impact of sex on longest duration of abstinence (LDA) and percent negative urine samples in 323 cocaine-using methadone patients from 4 randomized clinical trials comparing CM to standard methadone care. Overall, women had better treatment outcomes compared with men, demonstrated by an increase in both LDA and percentages of negative samples. Patients receiving CM also had significantly higher LDA and percentages of negative samples compared to patients receiving standard care, but sex by treatment condition effects were not significant. These data suggest that cocaine-using methadone patients who are women have better substance use outcomes than men in interventions that regularly monitor cocaine use, and CM is equally efficacious regardless of sex.