Effect of reinforcement probability and prize size on cocaine and heroin abstinence in prize-based contingency management.

Udi E. Ghitza, David H. Epstein, John Schmittner, Massoud Vahabzadeh, Jia-Ling Lin, & Kenzie L. Preston. (2008) Effect of reinforcement probability and prize size on cocaine and heroin abstinence in prize-based contingency management. Journal of Applied Behavior Analysis, 41, 539-549.

Although treatment outcome in prize-based contingency management has been shown to depend on reinforcement schedule, the optimal schedule is still unknown. Therefore, we conducted a retrospective analysis of data from a randomized clinical trial (Ghitza et al., 2007) to determine the effects of the probability of winning a prize (low vs. high) and the size of the prize won (small, large, or jumbo) on likelihood of abstinence until the next urine-collection day for heroin and cocaine users (N = 116) in methadone maintenance. Higher probability of winning, but not the size of individual prizes, was associated with a greater percentage of cocaine-negative, but not opiate-negative, urines.

DESCRIPTORS: computer automation, contingency management, methadone, operant conditioning, opiate, substance abuse