Evidence Rating for Outcomes
Drugs & Substance Abuse | Multiple substances |
Date:
This is an intervention strategy designed to reduce substance use disorders by rewarding positive behavior (e.g., negative drug tests) and withholding rewards when undesired behavior is exhibited (e.g., positive drug screens). The overall goal is abstinence from substance use. The practice is rated Effective for reducing alcohol, tobacco, and illicit drug use.
Practice Goals/Target Population
Contingency management interventions for substance use disorders are used in treatment and prevention programs and are designed to encourage positive behavior among program participants, with the overall goal of abstinence from substance use. Contingency management interventions reward program participants when they exhibit positive behaviors (e.g., negative drug tests). However, when program participants exhibit negative behaviors (e.g., positive drug tests), rewards are withheld, or participants receive punitive consequences.
Practice Theory
Contingency management interventions are based on operant conditioning. Operant conditioning is a learning process that aims to control and/or shape behavior through positive or negative consequences, typically known as rewards or punishments, respectively (Higgins and Petry 1999; Skinner 1938).
Program Components
In contingency management programs, the active treatment ingredient is incentives/rewards; participants are incentivized to exhibit positive behavior because doing so will result in a reward. Although there are different types of contingency management programs for substance use disorders, the use of incentives/rewards is common across all program types. Two of the most common contingency management programs for substance use disorders include Voucher-based Reinforcement Therapy (VBRT) and Variable Magnitude of Reinforcement Procedure, also known as the Fishbowl Procedure (Prendergast et al. 2006; Dutra et al. 2008).
In VBRT, when program participants submit samples that screen negative for drug use, they receive vouchers that have various monetary values. These vouchers can be traded in for goods/services. However, when samples indicate recent drug use, these vouchers are withheld. There are various reinforcement schedules that coincide with VBRT; for example, vouchers can increase with each successive negative drug sample, vouchers can reset to a lower value following a positive drug sample, or a bonus voucher can be provided after a certain number of negative drug samples (Prendergast et al. 2006).
In Variable Magnitude of Reinforcement Procedure, also known as the Fishbowl Procedure, participants can draw from a bowl that contains slips of paper, after providing a negative drug sample. Approximately half of the slips say “good job,” while the other half indicate a monetary reward, ranging from $1 to $100. Thus, with each draw, participants have a chance of winning a prize. After providing a certain number of successive negative drug samples, participants receive bonus draws from the bowl. As with other contingency management programs, if participants submit a positive drug sample, they are unable to draw from the bowl (Prendergast et al. 2006).
Although not as common, there are other variations of contingency management programs for substance use disorders. One program offers individuals the ability to take home doses of methadone after providing a certain number of negative drug samples. Other programs offer individuals affordable housing and work opportunities contingent on the receipt of negative drug samples and living a drug-free lifestyle.
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Drugs & Substance Abuse | Multiple substances
Overall, the results from two meta-analyses indicated that contingency management programs had a statistically significant impact on substance use disorders. Aggregating the results from 43 randomized controlled trials (RCTs), Prendergast and colleagues (2006) found a statistically significant overall mean effect size of 0.44, suggesting that participants in contingency management programs had lower rates of illicit drug use, alcohol use, and tobacco use than those who did not participate in such programs. Similarly, Dutra and colleagues (2008) aggregated the effect sizes from 14 RCTs and found a statistically significant mean effect size of 0.58, suggesting that participants in contingency management programs had lower rates of illicit drug use than participants in the control conditions. |
Literature Coverage Dates | Number of Studies | Number of Study Participants | |
---|---|---|---|
Meta Analysis 1 | 1970-2002 | 43 | 0 |
Meta Analysis 2 | 1992-2004 | 14 | 785 |
Prendergast and colleagues (2006) evaluated the effectiveness of contingency management programs for substance-using individuals. To be eligible for inclusion in the meta-analysis, studies had to be outcome evaluations of contingency management programs, delivered to adults or juveniles, and designed to treat dependence on alcohol, tobacco, or illicit drugs. Moreover, studies had to be published in English between 1970 and 2002, have used either an experimental design or quasi-experimental design, and have a total sample size of at least 10. Finally, only studies that included enough information to compute an effect size were eligible for inclusion. To identify studies, a comprehensive search was conducted of a variety of bibliographic databases using search terms that paired a particular technique (e.g., contingency management, token economy, behavioral contracting) with terms referring to the specific problem behavior (e.g., addiction, drug abuse, alcoholism, cocaine, tobacco).
A total of 1,150 studies were identified through this search strategy. After screening these studies across the eligibility criteria, a total of 81 studies were eligible for inclusion in the meta-analysis. However, of these 81 studies, only 47 were used in the final analysis given the limited number of information provided in some of the studies. All 47 studies were conducted in the United States, with 43 using experimental designs, and 4 using quasi-experimental designs. Approximately 70 percent of the included studies were conducted during the 1990s. Moreover, across the 47 studies, sample sizes ranged from 12 to 844, with a median sample size of 69. Finally, although attempts were made to locate unpublished literature, the included studies were all published studies. The target drugs of the included studies were marijuana, tobacco, cocaine, opiates, alcohol, and a combination of one or more drugs. Treatment approaches included cash, methadone take-homes, methadone dosage increase, methadone dosage decrease, graduation to next treatment phase, program discharge, vouchers, fee reduction, and reduction in clinic responsibilities.
To determine whether contingency management programs for substance use disorders are effective, both fixed effects and random effects models were used in the analysis; however, the main outcome of interest (illicit drug use, alcohol use, and tobacco use) was found using a random effects model.
Meta Analysis 2Using meta-analytic techniques, Dutra and colleagues (2008) analyzed the effect of contingency management programs on illicit substance use disorders, including cocaine, opiates, cannabis, and polysubstance abuse and dependence. To identify studies, PsycINFO was used to find articles published between 1840 and March 2005, using a variety of key search terms, including but not limited to cocaine, substance use, substance abuse, treatment outcome, contingency, and voucher. Additionally, MEDLINE was used to identify articles available between 1966 and March 2005, and Cochrane Central Register of Controlled Trials was used to identify studies for the first quarter of 2005. Both PsychINFO and MEDLINE searches were limited to those published in English.
To be eligible for inclusion in the meta-analysis, studies had to be investigations of the efficacy of individual psychosocial treatments for substance abuse/dependence (not including alcohol or nicotine abuse/dependence), and use randomized controlled trials, including a comparison group. Moreover, studies were limited to adult participants and to investigations on the efficacy of nonintensive outpatient treatments. Nonintensive outpatient treatment was defined as a maximum of three, 2-hour per week treatment sessions. Finally, studies had to include self-report outcomes of interest or toxicology screening outcomes of interest. Self-report outcomes of interest included 1) mean maximum number of days or weeks abstinent throughout treatment, 2) mean percent of days abstinent throughout treatment, 3) percent of sample abstinent for 3 or more weeks throughout treatment, 4) percent of sample demonstrating posttreatment/clinically significant abstinence, and 5) posttreatment scores on the Addiction Severity Index. Toxicology outcomes of interest included 1) mean number of negative drug screens throughout treatment, 2) mean percent of negative drug screens throughout treatment, and 3) percent of sample that demonstrated clinically significant abstinence.
Using this eligible criterion, a total of 34 studies were eligible for inclusion in the meta-analysis. Across the 34 studies, participants were approximately 35 years old and, on average, 62.2 percent male and 61.0 percent white (information about other races/ethnicities was not provided). However, of these 34 studies, 14 pertained to contingency management/voucher programs; the other 20 studies looked at other types of treatment that were not reviewed for CrimeSolutions. Across the 14 studies, the intent-to-treat sample (i.e., the sample size of the treatment condition) included 785 participants (this did not include the sample size of participants in the control condition, which was not provided). In the 14 studies, the treatment condition received contingency management, while the control condition received treatment as usual, motivational enhancement interviewing, 12-step facilitation, noncontingency management, or standard care.
Overall, to determine the impact of contingency management on illicit substance use disorders, an average mean effect size was created using Cohen’s d.
Two moderator analyses were conducted in the meta-analysis by Prendergast and colleagues (2006): the type of drug targeted for contingency management reinforcement (i.e., the type of drug that individuals were in treatment for), and the length of treatment. Regarding the type of drug targeted, contingency management interventions were statistically significantly more effective at treating opiate use and cocaine use than tobacco use. Regarding length of treatment, contingency management interventions of shorter durations were more effective than those of longer durations.
These sources were used in the development of the practice profile:
Dutra, Lisa, Georgia Stathopoulou, Shawnee L. Basden, Teresa M. Leyro, Mark B. Powers, and Michael W. Otto. 2008. “A Meta-Analytic Review of Psychosocial Interventions for Substance Use Disorders.” American Journal of Psychiatry 165(2):179–87.
Prendergast, Michael, Deborah Podus, John Finney, Lisa Greenwell, and John Roll. 2006. “Contingency Management for Treatment of Substance Use Disorders: A Meta-Analysis.” Addiction 101(11):1546–60.
These sources were used in the development of the practice profile:
Higgins, S.T., and N.M. Petry. 1999. “Contingency Management: Incentives for Sobriety.” Alcohol Research Health 23(2):122–27.
Skinner, B. F. 1938. The Behavior of Organisms: An Experimental Analysis. New York, NY: Appleton-Century-Crofts.
Age: 18+
Gender: Male, Female
Race/Ethnicity: White, Other
Targeted Population: Alcohol and Other Drug (AOD) Offenders
Setting (Delivery): Other Community Setting, Inpatient/Outpatient
Practice Type: Alcohol and Drug Therapy/Treatment, Alcohol and Drug Prevention, Individual Therapy
Unit of Analysis: Persons