The editorial team supports authors in the preparation of reviews by providing methodological advice, formulation and execution of search strategies, provision of RevMan software and other Cochrane Collaboration materials such as the handbook for authors and training and support as required on an ad hoc basis. Informal advice is available through the Managing Editor.
Drafting a review
Similar to protocols, reviews are drafted in a software package called "Review Manager", the current version of which is referred to as RevMan 5. Authors can download the most recent version for free from the RevMan website. The site also provides documentation and training materials. RevMan interacts with Archie, which acts as a central storage facility for both authors and the editorial teams. Authors use RevMan to write reviews, checking them in and out of Archie as necessary. This process can be initiated from either Archie or RevMan.
Authors should draft their review in RevMan, following the guidance provided and the Cochrane Handbook for Systematic Reviews of Interventions.
Literature search results will be sent to the contact author by the Cochrane information specialist.
Study selection - it is recommended that the trials included are randomised, pseudorandomised or controlled clinical trials which compare the test intervention with placebo or standard treatment. Other types of trials can be used where necessary. Selection of studies for inclusion in a review should be performed independently by more than one author. The editor assigned to the review will work to resolve differences in study selection between authors.
Assessment of methodological quality - Procedures for the assessment of methodological quality are under development. Advice on standard criteria for assessing quality will be given by the editorial team. Examples of quality assessment checklists are available. Methods are described in the Cochrane Authors Handbook which is available from the editorial team, on the Cochrane library and via Cochrane Training. In general:
- An accepted method of quality assessment should be used.
- Quality should be independently assessed by more than one author and the level of agreement should be reported in the review.
- The editor responsible for the development of the review will resolve difference in quality assessment between authors.
- Quality assessment will be reported in the methods and results sections of the review.
Data collection - it is recommended that the extraction of data is done independently by more than one author. The editor responsible for the development of the review will resolve difference in data interpretation between authors. Data verification with the person responsible for the study will not normally be required other than where the data is unpublished or confirmation of results are required.
Data from RCTs that have not been published will be eligible for use in systematic reviews, subject to verification of data by the primary investigator.
Copies of data extraction forms (for included studies) should be submitted to the group when a draft review is submitted for peer referee. Data extraction forms will be retained by the group, for reference or to aid a future review update, should an initial review author not be able to update a review. Data extraction forms will not be published nor used in any other way by the group or its members.
Analysis - Statistical guidance is available from the editorial base
Reporting of reviews
Discussion and conclusions section
The strength of the evidence should be categorised using the hierarchy of evidence scale detailed in CRD report 4, available from the editorial base. The applicability of the results should be commented on taking into account the applicability of the trials to use of the intervention in standard practice for treatment of the disorder. Cost benefit analysis will not be routinely performed. The use of non-RCT derived data when discussing results and drawing conclusions should be commented on in this section. Where applicable, other reviews will be cross-referenced in this section.
Tables and figures
Information in the excluded and excluded trials tables should be brief and structured to include the Study Identifier, Methods of the Trial, Participants, Interventions, Outcomes, and further Notes.
Each included study should ideally include a Risk of bias table including information on each study's and/or individual outcomes for bias from: sequence generation; allocation concealment; blinding; incomplete data, selective reporting or other means.
Studies in the excluded trials table should consist of those trials which were initially selected for assessment, but which later proved to be non-RCTs or ineligible for other reasons. Advice is available from the editorial team on the validity of trials for inclusion into the review.
Table of comparisons
Policies for the structure or order of outcomes are under development and depend to some extent on the outcomes we select as 'default' for this group.
The order of trials in the tables will be alphabetical, then by date. Trials will be named preferably by author surname (e.g. Smith 1998) or, where this is not possible, by trial group identifiers (e.g. Oesophageal Cancer Trials Collaborators Group OCTCG 1997).
There may be multiple publications from one trial. Such reports should be cross referenced to the original study, for example, a publication by Jones et al reporting data from the Oesophageal Trials Collaborators Group study of 1997, should be reported as Jones 1999 (OCTCG 1997).
Any factors which could be perceived as conflict of interest should be stated.
Summary of Findings
A summary of findings table should be included in a review, even for those with null results. The table should list the main results of the review, where possible limiting the number of outcomes reported to five or fewer.
Summary of findings tables may be created using the GRADE program. As GRADE is able to extract data from the RevMan file, we would advise making the creation of the summary of findings table the last step in the review development process. Further information on GRADE is available in English and several other languages.
Submitting a review
Using the Publication Wizard in Archie, authors mark the review for publication. This creates a special version of the document with the description ‘For publication’. Authors can then check the review out, make further changes, and check the document back in as a new draft version without affecting the version marked for publication.
In addition to submitting a final version of the review for publication via Archie, authors are also requested to send copies (print or electronic) of the following to the editorial office:
- Completed study eligibility forms
- Completed data extraction forms for included studies
- Completed review pre-submission checklist
Once submitted, the edtorial office will review the list of references for included studies. You may be asked to forward a copy of those which we do not have access to.
The Cochrane Database of Systematic Reviews is published monthly. The following table details the fixed dates (copy editing and publication) which we work to. You should aim to submit your protocol by the date in the "pre-peer review" column, in order to allow enough time to process the protocol for publication in that issue of the Cochrane Library.
At least three referees are asked to provide comments on each review, in general these will be: a person with experience of Cochrane methodology, a clinical expert and a consumer. These referees are usually from outside the editorial team, but editors may be asked to provide referee comments for reviews other than those for which they have editorial responsibility. In the case of methodological difficult or clinically contentious issues, comments may be sought from additional peer referees. Where possible, comments will be sought from the same peer referees who commented on the protocol.
After comments from referees have been returned to the authors, the authors are asked to modify the review as appropriate and return it to the Managing Editor with a commentary of the changes made and how these address the referees' comments.
Once approved by an editor, the editorial team will check and approve the review. Final approval for publication will be given by a Co-ordinating Editor. Copy editing will be performed by Wiley's copy editing service and authors will be expected to amend their reviews to reflect these copy edit comments before publication.
The policy for resolving disagreements between the editorial team and authors or between the authors themselves, about the content of the protocol, is to attempt to resolve such issues by informal discussion. In the event an issue cannot be resolved, the advice of the Senior Editor for the Cochrane Abdomen & Endocrine network will be sought.
Referees will be sent copies of the other referees' comments and the author's response, once the review is approved for publication.
Authors will be sent a final copy of the review along with a "permission to publish" form, a signed copy of which is required to be returned the editorial office prior to publication.