|A systematic review of the effectiveness of the community reinforcement approach in alcohol, cocaine and opioid addiction
|Roozen H G, Boulogne J J, van Tulder M W, van den Brink W, De Jong C A, Kerkhof A J
This review concluded that there is limited to moderate evidence for the efficacy of the community reinforcement approach (biopsychosocial multifaceted approach), with or without medication or contingency management, in alcohol and substance-related disorders. The exclusion of non-English language studies may affect the reliability of the findings and the authors' conclusions.
To evaluate the effectiveness of the community reinforcement approach (CRA) in alcohol, cocaine and opioid addiction.
MEDLINE, EMBASE, CINAHL, PsycINFO, ERIC, Biological Abstracts, LISA, an occupational safety and health database (OSH), Periodical Abstracts, SERFILE and Sociological Abstracts up to March 2003, and the Cochrane Library (Issue 2, 2002), were searched; the search terms were reported. The reference lists of identified trials and reviews were checked for additional studies. Only studies published in English were included in the review.
Study designs of evaluations included in the review
Randomised controlled trials (RCTs) were eligible for inclusion.
Specific interventions included in the review
Studies that evaluated a behavioural approach based on CRA principles (biopsychosocial multifaceted approach that acknowledges the role of environmental events and influences in habitual alcohol and drug abuse) were eligible for inclusion. Studies where only one aspect of CRA was investigated were excluded. Studies where CRA was combined with pharmacological treatments or maintenance were included. CRA was conducted using a range of regimens. The comparator was generally usual care.
Participants included in the review
Studies of people aged between 18 and 65 years with alcohol, cocaine or opiate abuse or dependence were eligible for inclusion. Studies including participants whose substance dependence was not the main diagnosis were excluded. Where reported, the mean age of the participants ranged from 28.5 to 39.9 years.
Outcomes assessed in the review
The primary outcome was abstinence, as determined by blood or urine samples or self-reports. Abstinence percentages within a follow-up period were acceptable. The secondary outcomes included addiction severity, frequency of substance abuse, and time to relapse. The outcomes reported included abstinence, number of drinking days, drinking time, time spent away from home, and time institutionalised.
How were decisions on the relevance of primary studies made?
Two reviewers independently selected studies for the review, with any disagreements resolved by consensus or referral to a third reviewer.
Assessment of study quality
Study quality was assessed in relation to 11 internal and 10 external validity criteria. These included randomisation, allocation concealment, withdrawals or drop-outs, similarity at baseline, blinding, intention-to-treat analysis, compliance, validity and relevance of outcome measure, description of intervention and comparators, follow-up, experience and training in CRA, use of tape recording, sample size and population details. Each item was scored as positive, negative or unclear. A study was considered high quality if 6 of the 11 internal validity criteria were positive. Where a criteria scored unclear, study authors were contacted for additional information. External validity criteria were used to indicate the degree of generalisability. Two reviewers independently assessed study quality.
Two reviewers independently extracted the data. The relative risk (RR, dichotomous variables) or mean difference (continuous variables), along with 95% confidence intervals (CIs), were calculated for each study.
Methods of synthesis
How were the studies combined?
A pooled RR or weighted mean difference (WMD) and 95% CI were calculated using a random-effects meta-analysis where two or more studies reported the same outcome for the same intervention. In addition, a narrative synthesis using a four-level rating system according to the strength of evidence (strong, moderate, limited, no evidence) was presented.
How were differences between studies investigated?
Separate analyses were conducted for short- (less than 4 weeks), intermediate- (4 to 16 weeks) and long-term (more than 16 weeks) outcomes. Differences between the studies were also discussed in the text. The authors discussed the potential for heterogeneity between studies in some analyses, however, no results of a statistical test for heterogeneity were presented.
Results of the review
Eleven RCTs (n=812) were included in the review.
Out of a potential score of 11 for internal validity, one RCT scored 5, three scored 6, one scored 7, two scored 8, two scored 9 and two scored 11.
Alcohol treatment (5 RCTs).
Three RCTs evaluated CRA alone. One reported a statistically significant decrease in drinking time with CRA (14% versus 79%, P<0.005), another no significant difference between CRA and usual car in relation to abstinence, but a decrease in the number of drinking days per week (0.22 versus 1.35), and the third a statistically significant increase in continuous abstinence ratings at 8 and 36 weeks. The number of drinking days was statistically significantly lower with CRA than usual care (2 RCTs; WMD -0.94, 95% CI: -1.60, -0.27).
Three RCTs evaluated CRA with disulfiram. Two reported a statistically significant decrease in time drinking with CRA (2% versus 55%, P<0.005; 3% versus 55%, P<0.01), and the third reported no statistically significant difference between CRA and usual care for any outcome when short- and long-term measures were analysed separately.
Cocaine treatment (4 RCTs).
Two RCTs compared CRA combined with abstinence-contingent incentives with usual care. The RR for cocaine abstinence was 3.75 (95% CI: 1.79, 7.87) at 4 weeks' duration and 5.09 (95% CI: 1.63, 15.86) at 4 to 16 weeks' duration. Two RCTs evaluated CRA combined with abstinence-contingent incentives with CRA alone. At 4 to 16 weeks' duration, the RR for cocaine abstinence was 1.73 (95% CI: 1.04, 2.88).
Opioid treatment (2 RCTs).
One RCT reported a statistically significant greater number of participants that achieved at least 8 weeks' continuous abstinence with CRA and incentives than usual care in a detoxification programme (47% versus 15%, p=0.03). This trend was seen at up to 24 weeks' duration but was no longer statistically significant.
One RCT reported CRA as being statistically significantly better than usual care in a methadone maintenance programme (84% of urine samples opiate negative compared with 78%).
There is strong evidence that CRA is more effective than usual care in relation to the number of drinking days, and that CRA with incentives is more effective than usual care or CRA without incentives in the treatment of cocaine abuse or dependence. There is moderate evidence that CRA with disulfiram is more effective in terms of drinking days, and limited evidence that CRA with incentives is more effective in an opioid detoxification programme and more effective than a methadone maintenance programme.
The review question was clear in terms of the population, intervention, outcomes and study design. An extensive search was conducted, but only studies published in English were included; this increases the likelihood of publication and language bias. Each stage of the review was carried out in duplicate, thus minimising the potential for error and bias. Each meta-analysis contained only 2 studies, and there were no more than 3 studies for any intervention/outcome combination. There was no obvious statistical test for heterogeneity and no graph to allow a visual inspection of between-study heterogeneity. The authors acknowledged that the lack of detail about the value of the different CRA elements is a limitation. Although the search and review methodology were sound, the language and publication restrictions, and the limited evidence available for each intervention/outcome combination, may affect the reliability of the findings and the authors' conclusions.
Implications of the review for practice and research
Practice: The authors did not state any implications for practice.
Research: The authors stated that further, larger RCTs in different countries and settings, that focus on the severity of addiction and have a follow-up of at least one year, are needed in this area.
The Ministry of Health, Welfare and Sports, grant number 3100.0019.
Roozen H G, Boulogne J J, van Tulder M W, van den Brink W, De Jong C A, Kerkhof A J. A systematic review of the effectiveness of the community reinforcement approach in alcohol, cocaine and opioid addiction. Drug and Alcohol Dependence 2004; 74(1): 1-13
Subject indexing assigned by NLM
Alcoholism /epidemiology /therapy; Cocaine-Related Disorders /epidemiology /therapy; Community Networks /statistics & numerical data; Humans; Opioid-Related Disorders /epidemiology /therapy; Randomized Controlled Trials as Topic /statistics & numerical data; Reinforcement, Social
Database entry date
This is a critical abstract of a systematic review that meets the criteria for inclusion on DARE. Each critical abstract contains a brief summary of the review methods, results and conclusions followed by a detailed critical assessment on the reliability of the review and the conclusions drawn.