Prize Contingency Management for Cocaine-Dependent Methadone Patients

Study Overview
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Brief Summary
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The investigators will randomize 300 cocaine-dependent methadone patients to 1 of 6 conditions: (a) a control group, (b) a contingency management condition that arranges a 100% probability of winning a prize with each draw and has 3 prize categories, (c) a contingency management condition that arranges a 31% probability of winning and has 3 prize categories, (d) a contingency management condition that arranges a 100% probability of winning and has 7 prize categories, (e) a contingency management condition that arranges a 31% probability of winning and has 7 prize categories, or (f) usual prize contingency management with a 50% probability of winning from 3 prize categories. Magnitudes of reinforcement will be identical across conditions, but lower overall probability conditions arrange for greater chances of winning larger magnitude prizes. The investigators expect that the new contingency management conditions will reduce cocaine use relative to the control condition, that 31% probability conditions will decrease drug use relative to 100% conditions, and that 7-prize category conditions will reduce drug use compared to 3-prize category conditions. In addition, the 31%/7-category condition is expected to be most efficacious. Results will be instrumental for further developing prize contingency management to improve outcomes of cocaine-dependent methadone patients.

Official Title
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Prize Contingency Management for Cocaine-Dependent Methadone Patients

Conditions
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Cocaine Abuse

Intervention / Treatment
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* Behavioral: prize contingency management


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: age > 18 years current DSM-IV diagnosis of cocaine dependence enrolled at the clinic for >3 months on a stable dose of methadone (no changes) for >1 month and not requesting a dose alteration submitted >1 clinic cocaine positive sample in the last 6 months English speaking pass a quiz related to understanding the informed consent form Exclusion Criteria: serious, uncontrolled psychiatric illness significant cognitive impairment in recovery from pathological gambling

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| No Intervention: Treatment Group A<br>Standard Care | |
| Experimental: Treatment Group B<br>100% probability of winning a prize with each draw and has 3 prize categories | Behavioral: prize contingency management<br>* Participants earn the chance to win prizes for the targeted behavior, cocaine abstinence.<br>|
| Experimental: Treatment Group C<br>31% probability of winning and has 3 prize categories | Behavioral: prize contingency management<br>* Participants earn the chance to win prizes for the targeted behavior, cocaine abstinence.<br>|
| Experimental: Treatment Group D<br>100% probability of winning and has 7 prize categories | Behavioral: prize contingency management<br>* Participants earn the chance to win prizes for the targeted behavior, cocaine abstinence.<br>|
| Experimental: Treatment Group E<br>31% probability of winning and has 7 prize categories | Behavioral: prize contingency management<br>* Participants earn the chance to win prizes for the targeted behavior, cocaine abstinence.<br>|
| Experimental: Treatment Group F<br>usual prize contingency management with a 50% probability of winning from 3 prize categories | Behavioral: prize contingency management<br>* Participants earn the chance to win prizes for the targeted behavior, cocaine abstinence.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| longest continuous period of cocaine abstinence |  | three months |