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Cochrane drugs and alcohol group: the development of systematic reviews of treatment outcome

Richard P. Mattick, Robert Ali, Marc Auriacombe, Marina Davoli, Fabrizio Faggiano, Michael Farrell, Marica Ferri, Walter Ling
DOI: http://dx.doi.org/10.1093/alcalc/36.2.109 109-111 First published online: 1 March 2001


— The aim of the Cochrane Collaboration is to promote review processes which address all aspects of health care and which can be viewed by clinicians to guide their day-to-day clinical practice. Recently, a Cochrane review group on drugs and alcohol has been developed. The Cochrane Review Group Editorial base is in Rome, Italy. There is an international editorial board with editors in the UK, Italy, France, Australia and the USA. So far, the group has published five reviews addressing treatment for opioid, cocaine and alcohol dependence. Additional reviews and protocols are in progress. A growing number of titles are registered with the group. Interested readers and potential reviewers and/or referees can contact the Cochrane Drugs and Alcohol Group Coordinator in Rome at the e-mail address: dacochrane{at}asplazio.it


Clinical interventions in day-to-day practice for alcohol and other drug problems are guided by the accumulated knowledge of the clinicians administering them. This knowledge derives partly from clinical experience, but also from trials of treatment, particularly randomized clinical trials of an active treatment vs some comparison of known efficacy. In order to bridge the gap between clinical practice and research findings, systematic narrative reviews have been the traditional approach to integrating and communicating information about the effectiveness of any given intervention. These traditional narrative or qualitative reviews have a great familiarity to any reader of any scientific journal, but they have been added to over the recent 20 years by the introduction of quantitative or meta-analytical review procedures. These meta-analytical review procedures have become recognized for their ability to integrate large amounts of information on a given therapy or intervention technique.


More recently, the development of the Cochrane database of systematic reviews through the Cochrane Collaboration has attempted to bring about a more precise method of preparing, maintaining, and disseminating systematic reviews of information on the effects of health care interventions on patients' outcomes. The Cochrane Collaboration was founded relatively recently, in 1992. The aim of the Collaboration is to promote review processes which address all aspects of health care and which can be viewed by clinicians to guide their day-to-day clinical practice.

There are several advantages to the Cochrane Collaboration approach to systematic reviews. First, the Cochrane Collaboration approach to reviews allows for randomized clinical trials or non-randomized comparative clinical trials on a particular topic to be subjected to a meta-analytical review procedure. Second, the meta-analytical review is complemented by a traditional qualitative review commenting on the studies included in the review and upon any interpretation issues. Additionally, any papers which could not be subjected to meta-analysis can be included in the narrative review, which is published with the quantitative results. In this sense, the Cochrane review processes are no different from any other combined qualitative and quantitative review procedures. However, the Cochrane approach has a number of distinct advantages over and above the normal review.

Reviews of any area of research findings typically have a relatively short half-life. They are published in journals and are rarely updated by the original authors. Such work is usually only updated when another set of authors undertakes the task of reviewing the entire literature to include any further studies published since the earlier review was completed. This approach to reviewing the literature leads to an amount of duplication of effort and an associated waste of resources. The Cochrane Collaboration approach to reviewing the research literature allows for further studies to be added into the existing reviews and their results are taken into account without necessarily re-reviewing all of the earlier articles. In this sense, the Cochrane reviews can be considered to be ‘living’ documents which can be added to and altered as new information becomes available.

In a similar vein, some published reviews may lead the authors of original research articles cited in the review to disagree with the way in which information from their work has been included or interpreted. Usually, the only recourse for the original researcher is to write a Letter to the Editor outlining the problem or issue, and this information may be published in the journal, but the published review would remain unchanged. As such, errors of interpretation or of facts present in published reviews are left unaltered.

By way of contrast, the Cochrane Collaboration has as a core component of its approach a mechanism which allows for errors in interpreting either the nature of the intervention or the results of the study to be dealt with in a progressive and open (or transparent) fashion. Authors of any original research can contact the editorial base and point out any errors of interpretation associated with the review. In the case where an error is identified, the publication can be amended to correct the review. This ability of the Cochrane Collaboration to respond to criticisms with actual adjustments to the published reviews ensures that any review which is presented through the Cochrane Collaboration is as accurate and up-to-date as possible. It also deals with bias on the part of reviewers. While the narrative review has been criticized as prone to bias, it is also the case that meta-analytical reviews can also be biased in how they interpret data. Again, the adjustments to reviews are possible, where an error of interpretation has occurred. The Cochrane review process thereby encourages correspondence between the reviewer and authors of original research papers. This can allow the reviewers the opportunity to request clarification of the results of a trial, or to seek additional statistics or data not included in an original research paper.

The drug and alcohol area, in terms of intervention studies, has a very substantial treatment-outcome literature which can be drawn upon to develop integrative reviews. Whether one looks at the use of pharmacotherapies to manage alcohol withdrawal states and dependence, psychosocial interventions for ‘excessive’ drinking and for alcohol abuse, intensive psychosocial interventions for alcohol dependence, or other pharmacological interventions for other drug problems such as heroin or cocaine dependence, there are a large number of extant papers.


Recently, a Cochrane Review Group on Drugs and Alcohol has been developed. The Cochrane Review Group editorial base is in Rome, Italy. There is an international editorial board with editors in the UK, Italy, France, Australia, and the USA. The opportunity is available for individuals with an interest in systematic reviews to contribute to the Cochrane database of systematic reviews. Publication in this database does not preclude the authors publishing the substantial work in an academic journal.

The Cochrane Review Group on Drugs and Alcohol is interested in receiving proposals for reviews of the effects of interventions on outcomes achieved by treatment procedures for individuals suffering from disorders of alcohol dependence or abuse. It is pointed out that the Cochrane review process, as it currently stands, only integrates information on treatment interventions using randomized clinical trials or quasi-experimental comparative clinical trials. As such, there is no capacity currently to include integrated reviews which do not address treatment outcome.

Drug and alcohol treatment is an area which is too frequently marked by disagreement. In such an environment, it is notable that a systematic review approach which does allow for ongoing updating and/or peer review can bring some better process of systematically integrating and disseminating the state of knowledge concerning different treatment interventions. Interested readers can contact the Cochrane Drugs and Alcohol Group Co-ordinator in Rome at the e-mail address: dacochrane{at}asplazio.it

The tasks of the group are:

  1. Identify and make accessible, within a specialized electronic database, all citations of randomized clinical trials (RCTs) and controlled clinical trials (CCTs) involving interventions for alcohol and drug misuse.

  2. Produce and update systematic reviews relevant to this field. All reviews are based on thorough literature searches. Considerable effort is expended in identifying both published and unpublished work. In order to avoid publication bias, systematic reviews need to be based on the most extensive proportion of all existing relevant studies. For this reason, the group is committed to establishing as comprehensive as possible a register of RCTs and CCTs which includes accessing unpublished literature, including materials available through pharmaceutical industries, trials conducted but not published, conference proceedings and grey literature where trial reports might be included.

  3. The activity of the group has now gathered momentum with a rapidly growing list of titles and proposals and a growing number of completed reviews. These include five reviews addressing treatment of opioid dependence [buprenorphine (Gowing et al., 2000a), naltrexone (Kirchmayer et al., 2000), and other opioid antagonists (Gowing et al., 2000b)], treatment of cocaine dependence with carbamazepine (Lima et al., 2000) and of alcohol dependence with opioid antagonists (Srisurapanont and Jarusuraisn, 2000). There are now six published protocols, including maintenance treatment with methadone (Mattick et al., 2000a; Faggiano et al., 2000), LAAM (Clark et al., 2000) or buprenorphine (Mattick et al., 2000b). Additional reviews (Gowing et al., 2000c,d) and protocols are in progress. A growing number of titles are registered with the group.


The Cochrane Collaboration is based on the enthusiasm of individuals. ‘By involving and supporting people of different skills and backgrounds’, as stated in the second principle of the Collaboration. Researchers, clinicians, consumers and people involved in the fields at different levels are encouraged to contact us to be involved in our activities. It is possible to propose a title for a review, or to contribute to the editorial process by acting as referee for protocols and reviews. As a hand searcher, it is possible to help us to identify relevant trials for inclusion in the reviews, and consumers can provide their point of view for the improvement of the readability and the consistency of the reviews.


  • * Author to whom correspondence should be addressed.


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