Amount of earnings during prize contingency management treatment is associated with posttreatment abstinence outcomes

Contingency management (CM) treatments that provide patients with the opportunity to earn chances of winning prizes of varying magnitudes are becoming increasingly popular. In the CM literature, magnitude of reinforcement is linked with effect sizes, such that CM treatments that provide larger magnitude reinforcement are more efficacious than those that provide lower magnitude reinforcement. With prize CM, even when magnitudes of overall expected prize earnings are constant, some patients win more prizes than others. Thus, patients who win larger overall amounts of prizes during treatment may have better outcomes than those who win fewer prizes. This study evaluated the impact of overall amounts of prizes won on long-term abstinence outcomes. The dollar amount of prizes won during prize CM treatments was determined from 78 cocaine-abusing methadone-maintenance patients who were randomized to prize CM treatments in three clinical trials. Abstinence three months following the end of the CM intervention was the primary dependent variable. The dollar amount of prizes won during CM treatment was a significant predictor of submission of cocaine-negative urine samples and self-reports of cocaine abstinence at the follow-up evaluation, even after controlling for other variables associated with long-term abstinence, such as pretreatment urinalysis results and longest duration of abstinence achieved during treatment. These results suggest that magnitudes of earnings during prize CM may impact outcomes and call for further experimentation of parameters related to the efficacy of prize CM.