Voucher-Based Incentives in a Prevention Setting (VIPS)
|Substance-related Disorders||Behavioral: Voucher-Based Reinforcement Therapy||Phase 2 Phase 3|
|Study Design:||Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Open Label
Primary Purpose: Prevention
|Official Title:||Voucher-Based Incentives in a Prevention Setting|
- Amount ($) Earned for Targeted Prosocial and Healthy Behaviors [ Time Frame: 24 Weeks ]Participants earned contingency management vouchers for targeted prosocial and healthy behaviors. 1 voucher = $1
- Proportion of Level 1 (i.e., Drug Negative Urines and Alcohol Negative Breath) Clean Urine Samples Provided at 12-month Follow-up, by Condition. [ Time Frame: 24 Weeks ]
- Self-reported Psychiatric Symptoms at 12-month Follow-up. [ Time Frame: 12 months ]As measured by the General Severity Index (GSI), a summary domain included on the Brief Symptom Inventory. The GSI combines information on both the number of symptoms described and the severity of those symptoms. Lower values on the GSI indicate less severe symptoms. Normative non-patient populations have been shown to have average GSI scores with a mean of 0.30 and a standard deviation of 0.31. Normative outpatient psychiatric patients have demonstrated GSI scores with a mean of 1.32 with a standard deviation of 0.72.
- Self-reported Sexual Behaviors at 12-month Follow-up [ Time Frame: 12 months ]Count of recent (past 30 days) male sexual partners.
|Study Start Date:||April 2005|
|Study Completion Date:||February 2008|
|Primary Completion Date:||February 2008 (Final data collection date for primary outcome measure)|
No Intervention: Control
Control condition receiving minimal incentives for service program attendance and participation.
Experimental: Contingency Management
Contingency management (Voucher-Based Reinforcement Therapy) intervention providing positive reinforcement for service program participation and attendance, enactment of prosocial/health behavior, and/or clean urine samples (i.e., no illicit drug use) and clean breathalyzer tests (i.e., BA < 0.05).
Behavioral: Voucher-Based Reinforcement Therapy
Participants were randomized into either the CM or control condition. Both conditions earned points for attendance and participation (max 364 points).
Participants in the CM condition also earned points for targeted health-promoting behaviors and for drug/alcohol abstinence. CM points for targeted health-promoting behaviors were not limited. Points for abstaining from substance use were awarded based on a Level 1 (recent abstinence for amphetamine, methamphetamine, PCP, and cocaine metabolites, as well as blood alcohol <0.05) urine sample.
Other Name: VIPS
Please refer to this study by its ClinicalTrials.gov identifier: NCT00607269
|United States, California|
|Friends Community Center|
|Los Angeles, California, United States, 90028|
|Principal Investigator:||Cathy J Reback, Ph.D.||Friends Research Institute, Inc.|
|Study Director:||Jesse B Fletcher, Ph.D.||Friends Research Institute, Inc.|