2.2 Controlled Studies of Continuing Care Treatment Interventions
Literature searches identified 20 controlled studies on the effectiveness of continuing care provided via various behavioral therapies or counseling interventions published since the late 1980s. Many of these studies have been summarized in earlier reports (McKay, 2001a
). These 20 studies are described in . Ten studies included patients with a primary alcohol use disorder diagnosis, whereas the other 10 included patients with drug dependence or a combination of drug and alcohol problems. Participants were graduates of inpatient or residential treatment programs in 12 studies (60%), and graduates of outpatient treatment programs in five studies (25%). In the remaining three studies (15%), most participants were graduates of inpatient/residential treatment with a minority from outpatient programs. It should be noted that at this point, the vast majority of individuals receiving treatment for substance use disorders in specialty care attend outpatient rather than inpatient or residential programs, which may limit the generalizability of the findings of this review.
Controlled Studies of Continuing Care
A systematic review of the methodological rigor of the studies included in review is beyond the scope of the article. However, several comments are in order concerning the study designs. Most of the studies had some strong methodological features. For example, 17 of 20 studies featured random assignment of patients to two or more conditions. In the other three studies, assignment to treatment condition was done on the basis of sequential cohorts and availability of the experimental condition. Follow-up periods were generally long, with 75% of the studies following patients for eight months or more, and follow-up rates were relatively good. Most studies included widely used measures of alcohol or drug use, which were often confirmed with urines samples or collateral reports. Many studies also went to some length to document adherence to treatment manuals, and controlled properly for therapist effects. Although data analytic approaches varied across studies, most included relevant baseline covariates in the analyses and some adjusted alpha levels for the number of outcomes examined.
The primary limitation of the studies, from a methodological standpoint, was low power to find group differences, particularly in the studies that did not yield positive findings. The average sample size in studies that failed to yield positive findings was 171, but only 104 with the very large Project MATCH (N=774) taken out of the calculation. Conversely, the average sample size was 164 in studies that did produce positive effects. With a sample size of 104, a treatment effect would need to be relatively large in order to be statistically significant (Cohen, 1988
). More modest effects, though potentially clinically meaningful, would not likely reach statistical significance with sample sizes of 100 or less.
Of the treatments provided in these 20 studies, the most common was some form of cognitive behavioral treatment (e.g., CBT, skills training, RP, etc.), which was provided in 10 studies. The next most common was standard addictions group counseling with a 12-step focus (5 studies), which was often “treatment as usual.” Other treatments provided in more than one study were home visits, interpersonal therapy, and comprehensive interventions. However, most of the interventions in these studies had at least some elements of cognitive-behavioral therapy, even if full CBT was not delivered. Most interventions were delivered at a treatment setting, although telephone counseling was used in five studies.
The studies in were classified according to whether or not a statistically significant treatment effect was obtained. Studies with positive results were those in which a significant treatment group difference was obtained on at least one of the primary substance use outcome measure(s), with no primary outcomes favoring the comparison or control condition(s). Studies with negative results were those in which no treatment group main effects were obtained on the primary substance use outcome measure(s), or mixed results were obtained, such as outcomes on one measure favored one group, whereas the opposite effect was obtained on the other specified primary substance use outcome measures. According to this classification system, 10 of the 20 studies yielded positive results. Not surprisingly, studies with minimal or no continuing care control conditions were somewhat more likely to yield a positive result (7 of 11, or 64%), compared to those with active continuing care comparison control conditions (3 of 9, or 33%).
Each of the 10 studies that yielded statistically significant positive results is described in more detail below. However, the fact that a finding is statistically significant does not always indicate that the effect is large enough to be clinically meaningful. Clinical relevance can be judged by the difference in proportions of dichotomous outcomes, such as abstinence rates or attendance at any continuing care sessions, and the odds ratios such analyses generate. A recent study published by Miller and Manuel (2008)
surveyed clinicians who were participating in the National Institute on Drug Abuse's Clinical Trials Network (CTN) to determine how large a treatment effect had to be in order for it to be considered clinically meaningful. These clinicians reported that differences between treatment conditions of 10-12 percentage points on dichotomous measures such as total abstinence or a biological indicator of alcohol or drug use were clinically significant. The 10 studies that yielded significant treatment effects were as follows.
McAuliffe and colleagues (McAuliffe & Ch'ien, 1986
) developed a continuing care treatment based on helping addicts learn self-sustaining alternative responses to stimuli previously associated with drug use, primarily through exposure to a community of recovery persons. Their program, which they called “Recovery Training and Self-Help,” consisted of professionally-led recovery training sessions, peer-led self-help styled meetings, and weekend recreational activity. Participants were asked to commit to participating for at least six months in the intervention components, and they could continue for up to one year. This intervention was compared in a randomized study (McAuliffe, 1990
) to a control condition that consisted of referrals to available continuing care services in the community and crisis intervention counseling from the study staff. Participants were opiate dependent patients who were completing a primary treatment episode, including residential care, detoxification from methadone maintenance, drug-free outpatient counseling, or half-way houses. One of the interesting features of this study was that it was implemented in the USA and in Hong Kong.
The primary outcome measure in this study was “favorable outcomes,” which the authors defined as total abstinence or use on less than a monthly basis, coupled with staying out of jail and providing follow-up data. The rates of favorable outcomes in the continuing care condition were 51% and 39% in the first and second 6-month segments, respectively, versus 39% and 25% in each time period in the control condition. The intervention also produced better employment outcomes and self-reported criminal activity outcomes than the control condition. Similar outcomes were generally obtained in the US and Hong Kong samples.
Foote and Erfurt (1991)
compared an extended follow-up procedure that provided up to 30 contacts over a one year period to standard follow-up procedures in EAP participants who had completed an episode of substance abuse treatment and returned to work. The EAP counselor was located at the workplace, and participants in the experimental condition received an average of 15 contacts over a year period, including 7 visits and 3 telephone calls, compared to an average of 3 contacts for those in the control condition. These contacts were designed to reinforce motivation, address difficulties that had emerged, and arrange for additional care if warranted. Although the planned schedule of contacts was weekly for one month, monthly for the next five months, and bi-monthly after that, the contact schedule reverted to once per week in the case of relapse or threat of relapse. The experimental condition produced better outcomes than the standard follow-up procedure on substance abuse treatment costs ($3,623 vs. $4,731, p< .05), number of substance abuse related hospitalizations (.69 vs. .81, p< .10), and substance abuse disability costs ($385 vs. $561, p< .10), when other relevant variables were controlled. However, these positive effects were relatively small, and substance use outcomes were not assessed in this study.
Patterson, MacPherson, and Brady (1997)
conducted a study that tested the effect of a continuing care protocol that consisted of home visits provided by a psychiatric nurse over a one-year period. The participants were alcohol dependent men, who had completed a six-week inpatient program in a rural area. All were first admissions for alcohol dependence. The home visit continuing care protocol consisted of weekly 1-2 hour visits for the first 6 weeks, and monthly meetings thereafter. When possible, the spouse or other family members were included. Telephone contact was also available for emergencies and advice between visits. The frequency of home visits could be increased following a relapse or other serious problems. The control condition was standard care at the facility, which consisted of review appointments at the hospital every 6 weeks.
Patients in the study were followed for five years. Results indicated that those in the home visit continuing care condition had substantially higher rates of continuous abstinence (36% vs. 6%, p< .001), were more likely to attend hospital meetings (24% vs. 9%, p< .05), and were less likely to report blackouts (36% vs. 55%, p< .05) or gambling (26% vs. 45%, p< .05). A limitation of this study was that all continuing care was provided by the same nurse, which means that treatment and provider effects were confounded. In addition, assignment to condition was not by randomization; instead, the control condition was provided when the continuing care nurse could not take on new cases (e.g., sick leave, annual leave).
O'Farrell, Choquette, and Cutter (1998)
studied the effect of providing couples behavioral marital therapy relapse prevention sessions to couples who had completed an initial course of behavioral marital therapy (BMT). The continuing care condition, which consisted of 15 sessions provided over 12 months, was compared to a no further treatment control condition. A total of 59 couples with an alcoholic husband were randomly assigned to the two conditions, and regular follow-ups were conducted out to 30 months post completion of the initial course of BMT.
Results indicated that the continuing care condition produced better drinking outcomes out to 18 months and better marital adjustment out to 30 months, as compared to a no continuing care control condition. For example, those receiving RP averaged about 94% days abstinent between months 4 and 18 of the follow-up, compared to 82% days abstinent in the control condition, which indicated a 15% increase in days abstinent. In addition, for those alcoholics with more severe drinking and marital problems, the continuing care condition produced better drinking outcomes over the entire 30 month follow-up (O'Farrell et al., 1998
). It should be noted that five couples who dropped out of the RP intervention very early in treatment were replaced in subsequent random assignments. This may have biased results to some extent in favor of the RP intervention in the intent-to-treat analyses.
Godley, Godley, Dennis, Funk, and Passetti (2006)
randomly assigned 183 adolescents who had completed at least 7 days of residential treatment for chemical dependency to two types of continuing care. The first condition was “usual care,” which consisted of referral to traditional intensive outpatient and standard outpatient treatment programs in the area. These programs varied considerably in the frequency and intensity of their adolescent services, ranging from 1 therapy session per week to several hours per day, five days per week. The experimental condition was referred to as “Assertive Continuing Care”, or ACC. ACC combined case management with home visits and a version of the Community Reinforcement Approach (CRA), adapted for adolescents (Godley, Godley, Karvinen, & Slown, 2001
). This comprehensive intervention includes a functional analysis of substance use behaviors, and skills training in a variety of areas including pro-recovery activities, relapse prevention, problem solving, communication, and so forth.
Results indicated that adolescents in the ACC condition were more likely to be successfully linked to continuing care services than those in the control condition, and received considerably more treatment, case management, and family services. For example, 94% of those receiving ACC were linked to continuing care, versus 54% of those in the control condition, which qualifies as a very large effect (Cohen's d= 1. 07, p< .001). Patients who received ACC were also significantly more likely to remain abstinent from marijuana over the 9 month follow-up than those in the control condition (41% vs. 26%, d= .32, p< .05). Outcomes on other substance use measures such use of alcohol and use of any substances also favored ACC over the control condition, but the results were not significant. One of the unique features of this study is that it is the only published experimental test of an adolescent continuing care intervention.
Sannibale et al. (2003)
evaluated the effectiveness of a structured continuing care program for patients with severe alcohol and/or heroin dependence who had completed residential treatment. The continuing care intervention (9 sessions over 6 months) was based on a coping skills approach as described by Monti, Abrams, Kadden, and Cooney (1989)
. The control condition was an unstructured approach that provided continuing care counseling sessions when they were requested by the patients. Patients in the control condition who wanted more than one continuing care session had to keep putting in requests for additional sessions.
The structured continuing care intervention produced a fourfold increase in attendance compared to the control condition (odds ratio= 4.3). However, rates of attendance were quite low in both conditions; the median number of sessions attended was 2 in the structured continuing care condition (range of 1-12) vs. 0 in the control condition (range of 0-4). The continuing care condition also produced one-third the rate of uncontrolled use of the principal substance of abuse, compared to that in the control condition (odds ratio = .3). The figures describing actual rates of uncontrolled use in each condition were not provided in this report. The conditions did not differ on time to first lapse or first relapse.
Bennett et al. (2005)
conducted a randomized study in the United Kingdom that compared standard group-based continuing care to an intervention referred to as “Early Warning Signs of Relapse Prevention Training” (EWSRPT), developed by Gorski (1995)
. The participants were alcohol dependent patients with a history of at least two relapses who had completed a 6-week day treatment program. The EWSRPT protocol is similar to cognitive-behavioral relapse prevention in several respects, but places more emphasis on identifying and addressing early signs of vulnerability to relapse, which under the Gorski model is a process that often unfolds over several weeks. EWSRPT was delivered via up to 15 individual sessions by counselors who had been trained and certified in this approach.
Patients in the EWSRPT condition had a lower probability of drinking heavily over the 12 month follow-up than those in the standard condition (45% vs. 26%, odds ratio= .43, p= .04). The authors report an additional statistic, number needed to treat (NNT) to prevent one relapse during a year period, which was 5. The EWSRPT intervention also produced fewer percent days drinking (p= .05, Cohen's d=.34) and fewer percent days of heavy drinking (p= .04, d= .31). Although the intervention also generated higher rates of abstinence from all drinking during the follow-up than the control condition (31% vs. 17%), this difference did not reach statistical significance (p= .08).
In a small study done in Taiwan by Horng and Chueh (2004)
, graduates of a short-term inpatient stay at a psychiatric center were recruited and assigned to either telephone continuing care or a no treatment control condition. The authors refer to the study as having a “quasi-experimental” design, but do not specify how participants were assigned to condition. The 30-60 minute calls were made in the 1st, 3rd
, and 13th
weeks. The therapists provided social support, health care guidance, medical information, and counseling on psychological problems. Results indicated that the telephone continuing care condition produced higher abstinence rates (50% vs. 24%, p= .02), better adjustment outcomes (p< .05), lower overall problem severity (as assessed by the Addiction Severity Index, p < .001), and lower readmission rates (9% vs. 38%, p< .005) over a 3 month follow-up than a no continuing care control group.
Brown, O'Grady, Battjes, and Farrell (2004)
investigated the effectiveness of a continuing care intervention for criminal justice clients who had completed outpatient treatment. The six-month treatment was provided at a facility close to the client's home, and was focused on developing and strengthening supports for drug free living in the client's community. To that end, the program made use of community organizations and agencies, involved family members, and addressed work-place issues. Services provided included case management, crisis intervention, support for drug-free functioning, skill building, assistance with problem solving, and a peer support group.
Compared to a no further treatment control condition, the continuing care intervention produced better outcomes on several key outcomes. These results were presented with odds ratios from logistic regression equations. Compared to those in the control condition, participants assigned to receive continuing care had less opiate use (OR= .26, p< .01), cocaine use (OR= .36, p< .05), any drug use (OR= .37, p< .01), and weekly drug use (OR= .20, p< .01).
McKay and colleagues (McKay et al., 2004
; McKay, Lynch, Shepard, & Pettinati 2005
) compared two clinic-based continuing care treatments, standard 12-step oriented group therapy (STND) and CBT relapse prevention (RP), with a telephone-based continuing care intervention (TEL). The TEL condition included CBT elements to reduce relapse risk, along with encouragement for and monitoring of the participant's efforts to make use of external supports like self-help programs. Participants in STND were scheduled to receive two group sessions per week, while those in RP were scheduled for one individual CBT/RP session and one group session. Participants in TEL were scheduled for one telephone call per week, which was supplemented with a group session in the first four weeks. The participants were all graduates of 4-week IOPs; half were dependent on cocaine and alcohol, 25% on alcohol only, and 25% on cocaine only. The continuing care interventions were provided for 12 weeks, and participants were followed up for 2 years from intake into continuing care.
Results indicated that the telephone condition produced better abstinence outcomes than standard group counseling, and better outcomes than CBT on several outcomes (e.g., cocaine urine toxicology, liver function measures indicative of heavy drinking). For example, rates of total abstinence within each three-month segment of the follow-up averaged around 55% in the TEL condition, vs. around 45% in the STND condition. Similarly, rates of cocaine positive urine samples during the follow-up averaged around 25% in TEL vs. 37% in STND.
Additional analyses indicated that the telephone condition worked best for patients who made reasonable progress toward achieving the goals of the IOP during the first 30 days of treatment, including abstaining from alcohol and cocaine, frequent attendance at self-help, making a commitment to total abstinence, and so forth. Patients who made poor progress toward these goals (20% of the sample) did better in standard group counseling than in the telephone condition (McKay et al., 2005
). Finally, mediation analyses indicated that the favorable effects of the telephone condition appeared to be at least in part due to the fact that it produced higher rates of self-help attendance during continuing care than group counseling, and higher levels of self-efficacy and commitment to abstinence during the subsequent three months (Mensinger, Lynch, TenHave, & McKay, 2007
2.3 Continuing Care Retention Studies
A number of studies have focused on identifying methods that can be used to increase engagement with and extended participation in standard continuing care approaches. Schaefer, Ingudomnukul, Harris, and Cronkite (2005)
found that greater use of continuity of care practices by counselors and case managers during outpatient
treatment predicted longer participation in subsequent continuing care. Specifically, greater efforts to coordinate care, connect the patient to resources, and provide continuity (i.e., retain same counselors or case managers in continuing care) predicted longer participation in continuing care, whereas efforts to maintain contact with patients after they left the first phase of treatment did not. Notably, continuity of care practices during residential
treatment did not predict retention in continuing care.
Hitchcock, Stainback, and Roque (1995)
studied the relation of patients' living situations while they were in continuing care to retention in continuing care. Results indicated that patients who were living in halfway or recovery houses had better retention and showed greater progress toward the goals of continuing care than those living in other forms of housing in the community. Schmitt, Phibbs, and Piette (2003)
found that patients who lived within 10 miles of a continuing care facility were 2.6 times more likely to seek treatment there following discharge from residential treatment than those who lived at least 50 miles from the facility. Finally, Shepard and colleagues found that providing continuing care counselors with a $100 bonus for each of their patients who attended at least 5 sessions of continuing care raised the percentage of patients who achieved that milestone from 33% to 59% (Shepard et al., 2006
Other studies have used experimental methods to test treatment enhancements designed to increase rates of entrance to and sustained participation in continuing care. The impact of case management on continuing care participation was examined in drug dependent patients (Siegal, Li, & Rapp, 2002
). Patients were randomized to receive standard primary and continuing care treatment, or standard treatment plus case management delivered during both primary and continuing care phases. Patients in the case management condition attended approximately 43% more continuing care sessions than those in standard care, and also had lower legal problem severity at 12 months.
Chutuape and colleagues (Chutuape, Katz, & Stitzer, 2001) wanted to increase the rates of successful transitions from brief inpatient detoxification to outpatient continuing care. These investigators randomly assigned patients completing a 3-day detoxification to one of three conditions: standard referral to continuing care, referral plus an incentive for completing continuing care intake procedures on the day of discharge from the detoxification program ($13), or incentives plus staff escort to the continuing care program. Rates of completed continuing care intakes was 24% in the standard condition, 44% in the condition with incentives, and 76% in the condition with incentives and a staff escort.
Lash and colleagues have been conducting a systematic program of research aimed at increasing attendance in continuing care (Lash, Burden, & Fearer, 2007
). The techniques this group has examined include contracts, prompts, and low-cost social reinforcements. In the contracting procedures, patients are provided with information on the success rates of patients who do and do not attend continuing care, and are asked to commit to participate in a specified amount of continuing care. Prompts consist of letters from therapists, appointment cards, automated telephone reminders for continuing care appointments, and letters and personal telephone calls following any missed continuing care sessions. The social reinforcement consists of personal letters from counselors with congratulations for attending sessions, certificates for completion of treatment milestones (e.g., 90 days of treatment), and medallions for attending specified numbers of continuing care sessions. The certificates and medallions were typically presented in front of other patients in the therapy groups.
In a first study (Lash, 1998
), patients in an inpatient program were randomly assigned to either receive or not receive a 20 minute aftercare orientation session, which included a contract to attend aftercare. Patients who got the orientation were almost twice as likely to attend aftercare as the control condition (70% vs. 40%) and they attended twice as many aftercare sessions (mean of 3.0 vs. 1.4). In a second study, Lash and Blosser (1999)
tested the effect of adding attendance feedback and prompts to the aftercare orientation and contract intervention. Results indicated that patients who received these additional components were more likely to attend aftercare (100% vs. 70%) and attended more aftercare sessions (4.38 vs. 2.35, p< .02, d= .80) than those who received the orientation and contract only, and they also had fewer hospital readmissions (5 in 21 participants vs. 15 in 20 participants).
Next, Lash and colleagues studied whether providing social reinforcement on top of the other intervention components further improved outcomes. The condition that included social reinforcement produced better attendance at aftercare groups over a 12 week period than the comparison condition (7.2 vs. 5.2 sessions attended, d= .56) (Lash, Petersen, O'Connor, & Lehmann, 2001
). A second study with the same design indicated that patients who received social reinforcement were twice as likely as those in the comparison condition to attend aftercare for at least two months (80% vs. 40%, p= .01), and had better scores on several other measures of aftercare participation. Moreover, the intervention with social reinforcement produced higher rates of abstinence at 6 months, as well as better alcohol use outcomes, than the very active control condition (Lash, Burden, Monteleone, & Lehmann, 2004
Most recently, Lash and colleagues (Lash et al., 2007
) have tested an enhanced version of their intervention, which they refer to as “Contracting, Prompting, and Reinforcing” or CPR. This version is extended out for one year, and targets self-help group attendance as well as aftercare participation. In this study, 150 graduates of a residential program were randomly assigned to the full CPR intervention, or to a usual care control condition (e.g., aftercare referral). It is noteworthy that unlike Lash's prior studies, the experimental condition was compared to a more minimal control, rather than to the full package minus one or two components. Results indicated that patients in the CPR condition were more likely to complete at least 3 months of aftercare (55% vs. 36%), remained in treatment longer (5.5 vs. 4.4 months), and were more likely to be abstinent at 12 months (57% vs. 37%) than those in standard care. Conversely, the intervention had no effect on attendance at self-help meetings. Further analyses suggested that the positive effect of CPR on abstinence outcomes was partly mediated by attendance in continuing care.
The work of Lash and colleagues is notable in several respects. First, they have conducted a careful and systematic program of research, in which the additive effect of each new component was determined by testing a version of CPR that included that component against a version that included all other components. Therefore, there is empirical evidence for each component of the intervention. Second, the intervention is relatively low cost, and can be added to treatment as usual—of any sort—relatively easily. The primary additional burden to the treatment program appears to be time spent by counselors in writing personalized notes and letters to patients at several points during their participation in continuing care.