Brief Summary

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.

Trial Health

On Track

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment

280

participants targeted

Target at P75+ for not_applicable

Timeline

Completed

Started Nov 2011

Longer than P75 for not_applicable

Geographic Reach

1 country

1 active site

Status

completed

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

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Study Timeline

Key milestones and dates

6.5 years study duration

First Submitted

Initial submission to the registry

July 22, 2011

Completed

3 days until next milestone

First Posted

Study publicly available on registry

July 25, 2011

Completed

3 months until next milestone

Study Start

First participant enrolled

November 1, 2011

Completed

6.5 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

May 1, 2018

Completed

Same day until next milestone

Study Completion

Last participant's last visit for all outcomes

May 1, 2018

Completed

Last Updated

March 13, 2019

Status Verified

March 1, 2019

Enrollment Period

6.5 years

First QC Date

July 22, 2011

Last Update Submit

March 11, 2019

Conditions

Cocaine Abuse

Outcome Measures

Primary Outcomes (1)

longest continuous period of cocaine abstinence
three months

Study Arms (6)

Treatment Group A

NO INTERVENTION

Standard Care