Writing a Systematic Review

Writing a systematic review

for Cochrane ENT

What is involved

Editorial policy

Advice, support and materials

Trusted evidence.

Informed decisions.

Better health.

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The Cochrane Collaboration. Registered in England as a company limited by guarantee No. 03044323 Charity Number 1045921.
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Introduction

Initial considerations

Preparing a systematic review for The Cochrane Collaboration is very different from submitting work to a traditional journal. Our systematic reviews are conducted and reported to strict methodological standards but the Cochrane Review Groups (such as Cochrane ENT) that comprise the Collaboration provide advice and support to review authors at every stage of the process, from devising the title to publication of the full review. Prospective authors should, however, also read the document ‘Managing expectations: what does The Cochrane Collaboration expect of authors, and what can authors expect of The Cochrane Collaboration?’

Before embarking on a review you should bear in mind the considerable commitment involved in becoming a review author for The Cochrane Collaboration. Not only are Cochrane reviews rigorously produced to high standards, in order to maintain their validity and accuracy they may be updated (to take into account new evidence, for example). Review authors are also required to respond to any comments on their work received from readers through The Cochrane Library's automated comments and criticisms system.

We recommend that lead authors work with at least two other co-authors and preferably more. Many of the tasks involved in systematic reviewing require at least two people working independently to avoid bias, but it also helps to spread workload. It is important that the author team brings a good variety of expertise to the review (e.g. clinical, statistical, information retrieval or perhaps a lay viewpoint). At least one author should have been a Cochrane author previously. Statistical support for your review is advantageous. We also expect one senior author to act as a guarantor.

Where to begin

Stage 1 - Contact the Managing Editor

Before you do anything else you should contact Jenny Bellorini, the Managing Editor, to register your interest in writing a review and discuss possible titles. It is important that:

your review does not duplicate work being undertaken elsewhere in Cochrane;
the review is achievable and that you choose a title which conforms to the Cochrane format. (Cochrane systematic reviews are generally concerned with the effectiveness of therapeutic interventions therefore they will normally take the format ‘Interventionfor[preventing or treating]disorder in [x]’);
your review falls within the scope of Cochrane ENT. There are several areas in which our scope overlaps with another Group, such as Cochrane Airways or Cochrane Acute Respiratory Infections.

When choosing your review subject, it can be helpful to look at a topic list. Details of the full scope of the ENT Disorders Group and an up-to-date list of ENT reviews already in progress is available on the Group’s website at or from the Managing Editor.

The Managing Editor will also send you the Cochrane ENT Notes for Authors and a Review Proposal Form.

The primary resource for all Cochrane authors is, however, the Cochrane Handbook for Systematic Reviews of Interventions. This is an essential guide to every aspect of preparing and maintaining a Cochrane review. The Handbook offers detailed guidance on issues such as developing a protocol, locating and selecting studies, quality assessment, data collection, and the analysis and presentation of results, including GRADE and ‘Summary of findings’ tables. It also contains valuable resources such as Cochrane highly sensitive search strategy for identifying randomised controlled trials and controlled clinical trials on the MEDLINE and EMBASE databases.

The Handbook is available online at is also included in the Collaboration's 'Review Manager (RevMan)' software (see below). If you have any difficulty accessing the Handbookyou should contact the Managing Editor.

In addition, in 2012 Cochrane issued new conduct and reporting standards for Cochrane reviews, known as Methodological Expectations ofCochrane Intervention Reviews (MECIR). The MECIR standards can be found online at or we can arrange to send you a booklet. Cochrane ENT reviews are expected to adhere to all of these standards.

Stage 2 - Complete the Review Proposal Form

The Review ProposalForm is used to supply basic details about yourself, your co-authors and the resources available to you (statistical support, library, IT etc.), and to provide us with a brief outline of your proposed review.

This form is circulated to the Cochrane ENT editorial board for their comments and approval. It is intended to highlight any potential difficulties at the outset and to ensure that the review begins on the right track.

If your proposal is accepted, your title will be formally registered with The Cochrane Collaboration, you will be set up with a user account for the Cochrane ‘Archie’ server and you can begin work on your protocol.

Starting your review project

Stage 3 - Writing the Protocol

After registration of the title we normally expect a protocol to be drafted withinthree months.

Workshops and training

At this stage many review authors find it helpful to attend one or more of The Cochrane Collaboration's workshops. These are regularly organised by the Cochrane Centres around the world. A summary of forthcoming workshops can be found online at and you should also check the website of your local Cochrane Centre for the latest new dates (list of centres:

The protocol workshop provides a good opportunity for discussing some of the issues important to your review. They normally begin with an introduction to Cochrane protocols and systematic reviewing, continuing with small group discussions. In these groups participants discuss their own review question including the types of studies, interventions, participants and outcomes they will consider. You will need to have thought about these issues beforehand. You will also need to be familiar with the ‘Cochrane Handbook for Systematic Reviews of Interventions' described above.

Analysis workshops are also available and often take place on the days following the protocol workshops, allowing you to attend both.

The Cochrane Collaboration training portal can be found at Here (once you have a registered title and Archie account) you can access online training modules. These have been developed to provide an introduction to some of the core skills and methods required for new authors of Cochrane systematic reviews of interventions. The training portal also includes details of face-to-face workshops, and there are online webinars and slide presentations.

Review Manager (RevMan) 5.3

Review Manager (RevMan) is the Collaboration's own software for preparing systematic reviews. It is the portal via which you can retrieve and enter the latest draft version of your protocol or review from the Cochrane server, ‘Archie’. It contains the full text of the review (or protocol), performs meta-analysis of the data and presents the results graphically. As you begin to work on your full review you will use it to enter and analyse your data. All protocols and reviews must be submitted to the editorial base in RevMan format via Archie.

A brief demonstration of RevMan is given as part of the protocol workshops.

RevMan can be downloaded from the Internet at You will need to input your user name and password at installation or by going to the Tools/Preferences/Connection tab). A self-paced RevMan learning exercise is also available within RevMan under the Help menu.

Designing a search strategy

Comprehensive and systematic searching is one the strategies used to minimise the potential for bias in Cochrane Reviews. Sam Faulkner is the ENT Disorders Group's Information Specialist/Trials Search Co-ordinator and, unless you have access to an Information Specialist locally, she will design the search strategies for searching the major medical databases for inclusion in your protocol and later run these for you across a comprehensive range of databases. Sam will also complete the ‘Search methods’ section of your protocol, which is standard across our reviews. This is normally done when you have written a rough draft of your protocol, as she will need to read your background section and criteria for study inclusion in order to design the search strategy. Sam can be contacted .

The editorial process

When you submit your draft protocol via Archie it will be subject to both an internal and external refereeing process. Firstly, the protocol will be proof-read and copy-edited by the Managing Editor, who will discuss with you any initial changes that should be made.

The protocol will then be sent to the Cochrane ENT editorial board and to an external (to the Group) content expert (peer referee) for their comments. We will also try to obtain feedback from a lay 'consumer' referee (e.g. a patient, carer) whenever possible.

We aim to complete the editorial process within about four to six weeks of receiving your protocol. All comments received will be collated by the Managing Editor and returned to you for action. We will ask for a response to each of the comments, either by an amendment to the protocol or by stating your reasons for resisting a change or disagreeing with the comment.

When we are satisfied that the protocol has been appropriately amended it will be given final approval by the Cochrane ENT Co-ordinating Editors and submitted to The Cochrane Library for inclusion in the next issue. All authors will be asked to complete a ‘License for publication’ form and a ‘Conflicts of interest’ form in Archie. As soon as all license forms have been completed, the protocol will be released for publication in The Cochrane Library (usually within two hours).

Stage 4 - Writing the Review

After publication of the protocol we expect a review to be produced within 12 months.

During the review process, Jenny Bellorini, the Managing Editor, can advise on the content, structure and format of your review, the use of RevMan and how to meet the Cochrane review conduct and reporting standards (MECIR). As described above Samantha Faulkner, our Trials Search Co-ordinator, can provide advice and help with your search strategies and, once your protocol has been accepted by our editorial panel, also offers a full searching service to all our review authors. She is also able to help with arranging translations if your search turns up foreign language studies that might be eligible for inclusion. As a Cochrane Group we have access to a wide range of expertise, both within Cochrane ENT and in the wider Cochrane Collaboration, including Methods Groups for specific issues e.g. the Non-Randomised Studies Methods Group and the Statistical Methods Group.

Review authors who are in, or visiting, the UK are welcome to come into the editorial base office in Oxford at any time, to discuss or work on their review.

GRADE and ‘Summary of findings’ table

A ‘Summary of findings’ table is mandatory in all reviews (see MECIR). Your GRADE ratings of evidence quality will absolutely central to the review: all key results are expected to be balanced against the quality of supporting evidence and this will also underpin your conclusions. For this reason, we strongly recommend that you create your ‘Summary of findings’ table and apply the GRADE system as early as possible in the review process: ideally once your data analysis is complete and before embarking on your write-up. In addition, the core editorial team would like to see your ‘Summary of findings’ table before you begin the write-up of your review, so please let us know when you reach this point.

The editorial process, on completion of the review, is identical to the process described above for protocols. Again, we aim to complete this within four to six weeks and will provide you with the collated comments to address. Final approval will be given by the Co-ordinating Editors.

Once your review is published, contact authors (though not co-authors) are entitled to a free subscription to The Cochrane Library, which will be arranged automatically.

Dissemination is an important strategy for Cochrane reviews. We will promote your review through all relevant channels, including social media. High-impact reviews may be selected for additional coverage, such as a press release.

Stage 5 - Updating the Review

It is Cochrane policy that reviews should be updated if this is warranted. The need for updating and the timing of this will depend on several factors, including the likelihood of new trials, the extent to which the question is of interest to patients, clinicians and policy-makers and the level of disease burden.

We no longer expect authors to update their reviews automatically. Whilst author teams may be given the opportunity to update reviews, this will not always be the case. The editorial base will be in touch when the review is deemed to require updating and may ask if you would like to update it, with or without support from the editorial base staff or new co-review authors, giving an indication of the timescale in which the update is required. At times, we may invite a new team to update the review. Needless to say, you will always retain authorship of the original published review.

Contact details

Jenny Bellorini, Managing Editor
E-mail:
Skype: jenny.bellorini

Samantha Faulkner, Trials Search Co-ordinator & Assistant Managing Editor

Email:

Skype: samfaulknercochrane

Postal address

Cochrane ENT Group

Department of Otolaryngology

West Wing
John Radcliffe Hospital
Headley Way
Headington
Oxford OX3 9DU

UNITED KINGDOM

Telephone

+44 1865 231051

Website

Twitter

@CochraneENT