From UConn Health, Farmington, CT.
Abstract
- Objective: To discuss the efficacy and generalizability of contingency management (CM) for the treatment of substance use disorders and design considerations for those considering implementing in clinical settings.
- Methods: Review of the literature.
- Results: CM is an efficacious treatment for substance abuse disorders that is widely generalizable across substance use disorders and patient characteristics. CM can be implemented in a number of treatment programs, including residential and outpatient settings, and it can be administered in both individual and group formats. Abstinence and attendance are the most commonly targeted behaviors in substance abuse treatment settings. Design features, including the selection of target behaviors, delivery methods, and reinforcers, are discussed. Schedule parameters, such as frequency, magnitude, immediacy, and escalation of reinforcement, are associated with overall impact of the CM program and are important considerations for those interested in tailoring CM protocols to their needs.
- Conclusion: CM is an efficacious option that is applicable to most substance abuse treatment patients. A number of demonstrations of real-world implementation have been published and suggest CM can be adapted with success to clinic settings. In adopting CM protocols, clinics should aim for those protocols with established efficacy; however, if adaptations are necessary, careful consideration should be given to modifications to minimize risks of undermining CM’s effects.
Key words: incentives; reinforcement; substance abuse treatment; dissemination; implementation.
Contingency management (CM) is a behavioral intervention that is efficacious in the treatment of substance use disorders (SUDs). CM uses a behavior analytic framework and applies principles of learning theory, particularly operant conditioning theory, to change client behavior(s) [1–5]. In basic terms, operant conditioning principles suggests that whether a behavior continues or not is a function of consequences [6]. Reinforced behaviors are more likely to occur in the future. Substance abuse can be viewed as a behavior maintained by the reinforcing effects of the drug itself [5], including the feel-good aspects of intoxication or relaxation and the amelioration of withdrawal symptoms. CM extends these same principles of to a treatment context, such that reinforcers for abstinent behavior are introduced to compete with the reinforcing effects of continued drug use [5].
In CM’s application to substance abuse treatment, drug-negative samples or treatment attendance are reinforced using tangible incentives with the goal of motivating continued abstinence and/or treatment engagement. When clients demonstrate these target behaviors, they earn incentives in the form of goods or services of value to the client, such as small electronics, gift cards, and toiletries. Despite the promising effects observed in research trials, real-world implementation efforts have not kept pace [7–9]. This review briefly discusses CM’s efficacy and highlights key features for professionals considering adopting this intervention. Demonstration efforts that illustrate how CM can be effectively implemented within the constraints and limitations of non-research, clinical settings are also presented.
Efficacy of CM
CM’s efficacy spans a number of SUDs, including cocaine, opioids, alcohol, nicotine, and marijuana [10–13], making it amenable for treatment of most SUD clinic populations. It generates larger effect sizes than other SUD treatments, including cognitive behavioral therapy [14], and it has been evaluated in a wide range of settings. Large-scale evaluations have been conducted in both intensive outpatient [15] and methadone maintenance [16] settings as part of the National Institute on Drug Abuse Clinical Trials Network, demonstrating consistent benefits of CM when added to treatment as usual. In the first of these 2 studies, Petry et al [15] randomized 415 stimulant users from 1 of 8 intensive outpatient clinics to treatment as usual or treatment as usual plus CM for alcohol and stimulant abstinence. CM participants submitted more substance-negative urine and breath samples, achieved continuous abstinence at significantly higher rates, and had longer treatment retention compared to those receiving treatment as usual. The parallel study [16] focused on stimulant use in clients from methadone maintenance clinics and found similar benefits of CM on stimulant abstinence. Beyond these settings, CM has been applied in a number of other contexts, including drop-in centers [17], vocational rehabilitation [18,19], job-skills training [20], and residential programs [21–23]. In addition, several group-based adaptations have been explored [17,24–27].
CM benefits most clients and generalizes across several demographic variables, including gender [28,29], race [30], housing status [31], and income levels [32–34]. Among clinical characteristics, CM is efficacious for those with co-occurring SUDs [35], other substance use [36], psychiatric disorders [37–39], medical problems [40–42], and history of transactional sex [43].
Design Considerations
Design features, including what behavior will be reinforced and how to do so, are among the first decision points for clinicians interested in implementing CM. One of the advantages of CM is that it has a high degree of flexibility in design, which means that it can be readily tailored to client populations and clinic needs. However, this flexibility can lead clinicians astray from the foundational principles of CM and unknowingly weaken the impact of the program. Below, some key considerations for CM protocol design are reviewed. For additional coverage of these topics, readers are referred to additional articles [1,2] or Petry’s comprehensive book on implementing CM [44]. In this review, published examples of CM’s application in real-world settings are presented, highlighting how CM has been adapted in these clinical efforts.
Target Behaviors
The selection of the target behavior will drive many of the subsequent program design decisions. As such, it is important to identify this feature early. Target behaviors must be achievable, objectively verifiable, and well defined. The most common CM targets are drug abstinence or therapy session attendance. CM has also been used to target other behaviors, such as medication adherence [45,46], treatment-related activities [47,48], and exercise [49–51]. Client self-report of behaviors or vaguely defined behaviors (eg, “good participation”) should be avoided. While some of the decisions related to CM protocols are flexible, the use of objectively verifiable target behaviors is a core feature that should not be neglected. If the behavior of interest cannot be objectively verified, an alternate behavior should be chosen.
Selection of the target behavior is often considered in hand with defining which population is eligible to participate in the CM program. Client characteristics are often forefront in this decision, but clinic-driven logistical issues or unmet needs may also play a role. A real-world example of this decision process is evident in the nationwide rollout of CM among the intensive outpatient programs within the Veterans Administration (VA). The VA identified a treatment need for those with stimulant use disorders, as this group did not have efficacious pharmacotherapy options available that targeted stimulant use. As such, the VA applied CM to patients with a focus on stimulant abstinence as the behavioral target [52]. For others, the decision may revolve around addressing underutilization of specific treatment resources (eg, outpatient groups, vocational rehabilitation) [53–56] or treatment needs among certain subgroups of clients, such as adolescents [57–59].
For abstinence targets, clinics would need to select one or more specific substances as the focus of the CM program. In general, targeting a single substance rather than multiple substances is more effective [10,13], is more straightforward for clients to understand, and allows more clients to access the reinforcers. Exposure to the reinforcers is necessary for CM to work; thus, setting a goal that is achievable for most clients should be a priority. Requiring abstinence from multiple substances means that some clients may never experience the reinforcer and thus cannot benefit from its effects at all. Some clinicians or administrators may initially have reservations about reinforcing single drug abstinence in the event that other drug use continues. However, targeting a single substance for reinforcement often results in reduced use of other substances [60]. Clinicians may find that this makes intuitive sense; a client with cocaine use disorder who is trying to maintain cocaine abstinence over a long period is likely to avoid using alcohol or other substances that might lead to relapse. For abstinence, objective verification through urine or breath specimens using tests that include validity checks is relatively straightforward.
Attendance is a popular target for clinics in part because it does not require additional staff time to collect specimen samples and it was the most commonly reported target behavior in samples of SUD providers who use incentives [61,62]. Objective verification of attendance is usually via a staff member, but expectations must be clear to both parties. Clinics should consider potential problems that may arise (eg, arriving late, leaving group early, excused absences) and carefully define and communicate expectations for the CM program. Piloting [19] the CM program with a small group of clients may be valuable in trouble-shooting challenges before wider implementation.