Using Contingency Management for the Treatment of Substance Use Disorders in Real-World Settings
Another approach, used in group-based CM, limits the number of patients who earn prizes per week [25,27]. For example, in a 2011 study by Petry et al, clients added slips with their name to a bowl for attendance and negative samples. Once all names were collected in the bowl, the group leader would pull a specified number of slips (eg, 3 slips per group). These individuals were eligible to draw from the prize bowl for prizes. This approach was associated with longer durations of consecutive abstinence and better treatment attendance relative to treatment as usual. However, clinics can control the overall program costs by limiting the number of patients eligible for prizes.
Frequency
Frequent reinforcement opportunities are ideal, and more frequent assessment is associated with larger treatment effects [10]. However, a number of factors, including which target behavior is selected and logistical issues specific to the clinic such as when groups meet, will play a role in determining the frequency of CM sessions. For abstinence targets, the substance targeted and type of test will largely determine the frequency of CM sessions. The goal would be to test at a frequency that would detect most or nearly all instances of use. For cocaine or opioids, this equates to testing 2 to 3 times weekly. Breath samples for alcohol or cigarette smoking would necessitate testing daily or multiple times per day to detect most instances of use because these tests have short windows of detection. CM protocols based on these breath tests have often had daily or twice daily CM sessions [77,78]; technological adaptations [77,79,80] or residential settings [21,23] may reduce burden to the client for assessment of these substances. Tapering the number of breath tests over time or transitioning from daily breath tests to once or twice weekly urine testing after abstinence is established is another approach [81,82].
Marijuana, on the other hand, poses difficulties because it is detectable in urine samples for up to 2 weeks following use. If relying solely on urine results for reinforcement, clients may not test negative for several days or weeks after last use, resulting in a delay of reinforcement. To address this issue, some CM programs targeting marijuana abstinence initially reinforce attendance in the first 2 weeks and then transition to reinforcing marijuana-negative drug samples for the remainder of the treatment period [48].
In general, more frequent CM sessions can translate to higher costs; however, infrequent reinforcement (ie, less than weekly) is not as effective [45]. In real-world applications, clinics often need to balance feasibility and costs with the ideal CM schedule. In abstinence-based CM, this compromise may result in a testing schedule that may not capture all instances of use. For example, while thrice-weekly testing may be ideal for cocaine or opioids, a twice-weekly schedule may be selected because it lowers costs and is more consistent with clinic schedules.
Immediacy
In general, clinics should aim to deliver reinforcement as immediately as possible, as delays between the target behavior and reinforcement are associated with decreased treatment effects [10,11,83]. For drug abstinence, onsite urine testing systems that provide immediate results are preferred over sending samples for laboratory testing. Clinics that do not have access to or who cannot afford specimen testing that allows onsite collection and immediate results might consider other options for target behaviors, such as attendance.
Immediacy of reinforcement is also important when targeting attendance. One clinic [53] implemented a program that offered a $50 incentive if clients attended 1 month of group therapy sessions. This approach was not effective and no clients earned the incentive for several months. After consultation, the clinic revised the incentive program to a daily drawing for attendance using the fishbowl method, thereby decreasing the delay between the behavior and its consequence. This example illustrates not only problems with delayed reinforcement but also the common mistake of setting expectations for the target behavior too high. Attending a month of group therapy sessions is a high bar that few patients will achieve, resulting in a system that mostly rewards those already doing well [19]. In contrast, attending a single group session in order to earn reinforcers is a reachable goal and increases the likelihood that more clients are exposed to the reinforcers. These small steps (ie, attending a single group or submitting a single drug negative urine) encourage initiation of the behavior(s) targeted. Other features, such as escalation (discussed next), aim to sustain the behavior over time.
Escalation
Escalation involves increasing the amount of reinforcement for each consecutive target behavior. In the voucher programs, the amount earned per negative sample may increase for each consecutive negative sample (eg, $2.50 for the first negative sample, $3.00 for the second, $3.50 for the third, and so on). For prize-based programs, the number of draws escalates with consecutive performance (eg, 1 draw for the first group attended, 2 draws for the second, 3 for the third, and so on). Protocols that include escalation generate larger effects than those that have a set, flat incentive amount even when total costs are the same across comparison conditions [73].
