A randomized trial adapting contingency management targets based on initial abstinence status of cocaine-dependent patients.

Contingency management (CM) is highly efficacious for treating drug use disorders. Often, CM interventions reinforce submission of negative toxicology samples with vouchers exchangeable for retail goods and services (Higgins, Budney, Bickel, Foerg, Donham, & Badger, 1994; Higgins, Wong, Badger, Ogden, & Dantona, 2000b) or chances to win prizes (Petry et al., 2004; Petry et al., 2006a; Petry, Alessi, Hanson, & Sierra, 2007; Petry, Alessi, Marx, Austin, & Tardif, 2005a; Petry, Martin, Cooney, & Kranzler, 2000; Petry, Martin, & Simcic, 2005b; Petry et al., 2005c). A meta-analysis of psychosocial treatments concluded that CM was the intervention with the greatest effect size in treating substance use disorders (Dutra et al., 2008). Although CM is efficacious, it is rarely implemented in practice. A primary obstacle is cost. Voucher CM typically provides up to $1000 in incentives, and reducing magnitudes of vouchers available renders CM less effective (Dallery, Silverman, Chutuape, Bigelow, & Stitzer, 2001; Higgins et al., 2007; Lussier, Heil, Mongeon, Badger, & Higgins, 2006). Prize CM usually arranges $250-$400 in expected maximal earnings and is efficacious over that range (Peirce et al., 2006; Petry et al., 2004, 2005a,b,c, 2006a, 2007). However, prize CM is also magnitude dependent, and reducing reinforcement likewise reduces efficacy (Petry et al., 2004), but primarily among patients with greater severity of drug use problems; patients with lower severity of drug use problems provided mostly negative samples regardless of reinforcement contingencies (Petry et al., 2004). Adaptive research designs (Collins, Murphy, & Strecher, 2007; Murphy, Collins, & Rush, 2007; TenHave, Coyne, Salzer, & Katz, 2003) utilize aspects of patients' functioning as a basis for randomization to treatment conditions. These designs are gaining popularity in clinical research but have not been applied in CM study designs. Patients who initiate outpatient treatment while actively using drugs have a poor prognosis (Alterman et al., 1997; Alterman, McKay, Mulvaney, & McLellan, 1996) and may require greater magnitude reinforcement to achieve abstinence (Preston, Goldberger, & Cone, 1998; Silverman, Chutuape, Bigelow, & Stitzer, 1999; Stitzer et al., 2007). In re-analyzing data based upon sample results at treatment initiation, Stitzer et al. (2007) reported that CM that reinforced abstinence with up to $400 in prizes benefited only patients who began treatment with a negative sample and not patients with an initially positive sample. They concluded that more intensive interventions may be necessary in patients who begin treatment while still using drugs. Identifying a level of reinforcement magnitude sufficient to enhance outcomes in more severely drug dependent patients but still fairly low in cost could increase CM adoption. Frequent toxicology testing is another obstacle to CM administration in practice. In addition to costs of the tests themselves, it is often not feasible for clinicians to collect samples two or three times per week (Petry & Simcic, 2002). Reinforcing attendance, rather than abstinence, may allow CM to be more readily integrated into practice, and may be equally beneficial for patients who initiate treatment while cocaine abstinent. Studies of patients enrolled in outpatient substance abuse treatment programs reveal low rates of drug use while such patients remain engaged in treatment. For example, in the National Drug Abuse Clinical Trials Network (CTN) study (Petry et al., 2005c), over 88% of samples collected tested negative for cocaine, opioids and alcohol. Recent data suggest that CM that reinforces attendance can improve treatment engagement (Alessi, Hanson, Wieners, & Petry, 2007; Ledgerwood, Alessi, Hanson, Godley, & Petry, 2008; Petry, Martin, & Finocche, 2001; Sigmon & Stitzer, 2005), which in turn may be associated with reduced drug use (Simpson, Joe, & Broome, 2002). However, reinforcing attendance alone could produce an undesired effect of patients attending treatment to obtain reinforcement while continuing to use drugs. Unlike CM protocols that reinforce abstinence, reinforcement values generally do not reset to lower values if drug use occurs when attendance alone is reinforced. This study tested the efficacy of a CM condition that reinforced attendance only and, at the same time, frequently assessed drug use to ascertain if patients would relapse and attend treatment while using substances. The present study had two primary aims. The first was to compare the efficacy of two magnitudes of reinforcement in patients who began treatment with cocaine-positive samples. We expected that higher magnitude CM would be more efficacious than lower magnitude CM in improving durations of abstinence and proportions of negative samples in this subset of patients. The second purpose was to evaluate attendance-based CM in patients who initiated treatment while cocaine abstinent. We anticipated that attendance- and abstinence-based CM would be equally efficacious in engendering longer durations of objectively-confirmed abstinence than standard care in these patients. We also compared patients initiating treatment with cocaine-positive versus cocaine-negative samples, with the hypothesis that the former group would have poorer overall outcomes. Finally, we evaluated long-term effects of the interventions on abstinence at month 9 follow-up evaluations.