An adaptive approach for identifying cocaine dependent patients who benefit from extended continuing care.

Substance use disorders often have a chronic course, with afflicted individuals cycling through periods of abstinence, sporadic use, and heavy use (Hser, Longshore, & Anglin, 2007; McKay, 2009a; McLellan, Lewis, O’Brien, & Kleber, 2000). Wider use of effective continuing care has been recommended to increase rates of sustained recoveries and limit the severity and duration of relapse episodes that do occur (Dennis & Scott, 2007; Humphreys & Tucker, 2002; McKay, 2009a; Miller & Weisner, 2002). Continuing care interventions with longer durations and active efforts to deliver the intervention tend to show larger effects (McKay, 2009b; McKay et al., 2010; Scott & Dennis, 2009). Although effective, extended continuing care models for substance use disorders are labor intensive and add to the cost of treatment. It is therefore important to determine which patients are most likely to benefit from these interventions. One such group may be patients who are using drugs or alcohol immediately prior to intake, or who continue to use early in treatment. For example, prior studies shown that cocaine dependent patients who are using cocaine immediately prior to treatment have worse retention and drug use outcomes than those who have stopped using (Ahmadi et al., 2009; Alterman et al., 1997; Kampman et al., 2001). Similarly, patients who continue to use drugs or alcohol in the first few weeks of treatment are at higher risk for early dropout and poor outcomes (Higgins, Badger, & Budney, 2000; McKay et al., 1999, McKay et al., 2005; Plebani, Kampman, & Lynch, 2009; Preston et al., 1998). In a study by McKay et al. (1999), patients who continued to use cocaine or alcohol during a 4-week intensive outpatient treatment program had worse outcomes than those who remitted substance dependence during that period. However, providing coping-skills based relapse prevention continuing care to these patients produced better cocaine and alcohol use outcomes than standard care. Conversely, there were no continuing care effects in remitted patients. Alcohol use has also been reported to precipitate cocaine relapse in cocaine dependent individuals (McKay, Alterman, Rutherford, Cacciola, & McLellan, 1999). The goal of the present study was to determine whether substance use status immediately prior to intake and during the first few weeks of treatment could be used to identify patients who would most benefit from extended continuing care. Therefore, the study was designed to develop an adaptive model of treatment (McKay, 2009a; Murphy et al., 2007), in which patient progress is used to determine whether standard care needs to be augmented to achieve optimal outcomes. Participants were patients enrolled in publicly-funded intensive outpatient programs (IOPs); all were cocaine dependent and the majority were also alcohol dependent. Therefore, it was hypothesized that participants who were actively using cocaine or alcohol at intake or in the first few weeks of treatment would have worse substance use outcomes than those who had successfully achieved initial abstinence, but would benefit to a greater degree from extended continuing care. However, because patients with active use prior to or early in treatment are at greater risk to dropout, we also evaluated the impact of providing low-level incentives for continuing care session attendance. Incentivizing attendance has increased attendance rates in treatment for substance use disorders, although the magnitude of effects has been somewhat smaller than when abstinence is incentivized (Bride & Humble, 2008; Businelle et al., 2009; Lussier et al., 2006; Petry et al., 2006). A preliminary analysis of continuing care participation in the present study indicated that incentives dramatically increased the number of sessions attended in the first year of the follow-up (Van Horn, et al., 2011). The extended continuing care intervention in the study, Telephone Monitoring and Counseling, included a combination of telephone and in-person sessions. The intervention includes cognitive-behavioral therapy (CBT)-like elements, such as regular monitoring of current substance use and other risk and protective factors, identification of upcoming high-risk situations, and selection and rehearsal of coping strategies; and linkage to community supports (McKay et al., 2010). The telephone is well suited for the delivery of extended continuing care, because of added convenience for patients, reductions in barriers to attending clinic-based care, and greater flexibility in scheduling sessions (McKay, 2009b). Two prior studies have shown that this intervention produces better drug and alcohol use outcomes than standard care (McKay et al., 2005; McKay et al., 2010). In the present study, participants were cocaine dependent IOP patients (N=321) who were randomly assigned to standard care only (i.e., treatment as usual, or TAU), TAU and Telephone Monitoring and Counseling (TMC), or TAU and TMC plus incentives (TMC+), and followed for 24 months. Because many study participants were also dependent on alcohol and had a history of other drug use, the first outcome measure was abstinence from all drugs in a given follow-up period, as indicated by both urine toxicology tests and self-report, and no reported days of heavy alcohol use during the period. Cocaine urine toxicology was included as a second outcome, to provide a measure specific for cocaine use only. The following hypotheses were tested: TMC and TMC+ will produce better outcomes than TAU. Cocaine and alcohol use at intake or early in treatment will predict worse outcomes. Treatment effects favoring TMC and TMC+ over TAU will be larger in participants with cocaine or alcohol use at intake or early in treatment. Adding incentives for attendance to TMC will produce larger treatment effects.