Randomized trial of continuing care enhancements for cocaine-dependent patients following initial engagement.

Objective: The effects of cognitive-behavioral relapse prevention (RP), contingency management (CM), and their combination (CM + RP) were evaluated in a randomized trial with 100 cocaine-dependent patients (58% female, 89% African American) who were engaged in treatment for at least 2 weeks and had an average of 44 days of abstinence at baseline. Method: The participants were from intensive outpatient programs, which provide 10 hr per week of group counseling. The CM protocol provided gift certificates (maximum value $1,150; mean received = $740) for cocaine-free urines over 12 weeks on an escalating reinforcement schedule, and weekly individual RP sessions were offered for up to 20 weeks. Average number of RP sessions attended was 3 in RP and 13 in CM + RP. Results: Generalizing estimation equation analyses over 18 months postrandomization showed significant effects for CM (but not RP) on urine toxicology and self-reported cocaine use (p = .05), with no significant CM x RP interactions. Secondary analyses indicated CM + RP produced better cocaine urine toxicology outcomes at 6 months than treatment as usual, odds ratio [OR] = 3.96 (1.33, 11.80), p < .01, and RP, OR = 4.89 (1.51, 15.86), p < .01, and produced better cocaine urine toxicology outcomes at 9 months than treatment as usual, OR = 4.21 (1.37, 12.88), p < .01, and RP, OR = 4.24 (1.32, 13.65), p < .01. Trends also favored CM + RP over CM at 6 months, OR = 2.93 (0.94, 9.07), p = .06, and 9 months, OR = 2.93 (0.94, 9.10), p = .06. Differences between the conditions were not significant after 9 months. Conclusions: These results suggest CM can improve outcomes in cocaine-dependent patients in intensive outpatient programs who have achieved initial engagement, particularly when it is combined with RP.