A randomized trial of employment-based reinforcement of cocaine abstinence in injection drug users.

High-magnitude and long-duration abstinence reinforcement can promote drug abstinence but can be difficult to finance. Employment may be a vehicle for arranging high-magnitude and long-duration abstinence reinforcement. This study determined if employment-based abstinence reinforcement could increase cocaine abstinence in adults who inject drugs and use cocaine during methadone treatment. Participants could work 4 hr every weekday in a workplace where they could earn about $10.00 per hour in vouchers; they were required to provide routine urine samples. Participants who attended the workplace and provided cocaine-positive urine samples during the initial 4 weeks were invited to work 26 weeks and were randomly assigned to an abstinence-and-work (n = 28) or work-only (n = 28) group. Abstinence-and-work participants had to provide urine samples showing cocaine abstinence to work and maintain maximum pay. Work-only participants could work independent of their urinalysis results. Abstinence-and-work participants provided more (p = .004; OR = 5.80, 95% CI = 2.03-16.56) cocaine-negative urine samples (29%) than did work-only participants (10%). Employment-based abstinence reinforcement can increase cocaine abstinence.