Therapy development of group contingency management in methadone treatment: Pilot 1---the application of a percentile schedule to enhance attendance behaviors and cocaine abstinence

In an effort to adapt a prize-based attendance and abstinence reinforcement program to the group therapy modality typically found in community substance abuse treatment, this study applied a contingency management (CM) procedure to behavior outcomes of the group as a whole. An algorithmic shaping percentile schedule was used to establish the outcome criteria determining group access to prize bowl drawings. Both the shaping schedule and hypothesized positive social support secondary to interdependent group contingencies aimed to initiate cocaine abstinence among cocaine abusing methadone-maintained participants having initial low rates of cocaine abstinence. In a multiple baseline across behaviors with reversals design, the procedure was applied to four target behaviors in sequence: incentive group attendance, urinalysis appointment attendance, opiate and cocaine abstinence. Results demonstrated clear improvement in group attendance during the shaping schedules. Effects on opiate abstinence were promising but not definitive; an increase in magnitude of reinforcement yielded a better response. There were no effects on cocaine abstinence using the percentile schedules tried. When shaping was conducted by an experienced psychologist in conjunction with an average 4-fold increase in reinforcer magnitude, 55% achieved some abstinence (compared to 18% in baseline). Participants were monitored for safety due to concern about coercion; no instances of physical violence occurred and infrequent instances of verbal negativity were managed using typical outpatient procedures. Results indicate that interdependent group CM is efficacious for attendance, and a feasible and acceptable procedure with appropriate monitoring. Future studies are needed to determine effective and appropriate shaping and reinforcement schedules in group CM to increase drug abstinence.