What should happen after the search is complete, should we immediately start writing the systematic review?

Once you have done the first version of the search, you may find that you have too many results or not many results at all.

Too many results?

If you have too many results it is likely that your search was too broad and that rather than manually checking each reference, using the filters provided by the search engines could help refine the results. Some possibilities for refining the search are to limit it to a specific language (English, for example), or to just searching the abstract and title, rather than the full text.

Too few results?

This might be what you expected and could be the basis for the systematic review, highlighting the need for more studies in a particular area. However, you may want to broaden your search if you feel that not all relevant manuscripts have been captured. This could be done by including additional keywords, or removing limits (e.g. looking for all studies and not just those in humans).

What if the number of results seems fine?

Once you are happy that the search has captured all the appropriate results, you will want to save a list of the results, including references, title and abstract, as well as recording the initial number of results found. You will need to keep track of this for the PRISMA flowchart. These results should then be distributed to the individuals that have been allocated as reviewers and they should review each abstract and decide whether it meets the inclusion criteria defined for the review. These criteria should have been defined before the search and it is important that both reviewers use them. The reason why each abstract is rejected should also be recorded. This can be done according to the PICOS, with abstracts rejected according to not containing appropriate participants, intervention, comparator, outcome or setting, or for another reason which should be recorded.

In a perfect world both reviewers will select the same abstracts at this stage, however, if they do not, an additional reviewer should arbitrate whether the abstract should be kept. If there is confusion, the abstract should be kept, for full text review (the next step).

After the abstracts have been filtered, should we start writing?

No. You will want to get the full version of each reference and these will also need to be reviewed, in a similar manner to the abstracts, to ensure that no inappropriate references are included. At this stage, you can note any manuscripts in the references that also look appropriate for the systematic review. This will enable you to check that they have been included and if not they can be added (and noted on the PRISMA flowchart).

This process of filtering can be long and tedious, however, it should enable all the relevant literature for the systematic review to be identified. It is at this stage that the writing can commence!

Don’t aim to write scientifically, aim to write well

When we write something we are often trying to convey who we are, or more specifically who we want to be perceived to be, to the writer. This means that we will alter the tone of our writing according to the audience, an email to a friend will be different from a job application letter. When writing a scientific manuscript it is, therefore, often the case that people write it in a manner they perceive to be ‘scientific’.

What is scientific writing?

When I say scientific writing I mean writing with many technical words intended to convey the idea that you know what you are talking about. These technical words will often be jargon and in some cases might be better conveyed using ‘everyday’ language. This will limit the audience of your work to others who understand the jargon that you are using, as well as potentially making the manuscript more difficult to read.

How can scientific writing be avoided?

Once you have written your manuscript you should get other people to review it, at least one of whom should be reviewing the language used. This should be someone you trust as the feedback might not be what you expect from your ‘perfect’ draft. When you ask this person to review the manuscript you should specifically ask them to keep an eye out for overly ‘scientific’ language.

A second thing that you can do is to read the draft out loud once you have written it. By reading out loud, even if it seems odd, you can identify any issues with ‘pacing’ or where jargon might interfere with the ‘flow’ of the manuscript.

A word of caution

Do not remove scientific words if they are necessary, you should not dumb down just to improve readability. This is a tightrope that you will have to walk, but hopefully by asking others for their opinions this will help navigate the issue.

What are the next steps after the first draft is written?

Once you have produced your first draft and your co-authors have reviewed it, your aim should be to address the comments and get the manuscript submitted to your chosen journal as soon as possible. How you manage this will depend upon the comments you receive.

If they are minimal

  • Make the suggested changes, or ignore comments if you have a reason to do so and can explain it to the person who made the comment
  • Ensure the manuscript is in the style requested by the journal
  • Confirm that all authors are happy to submit
  • Submit to the journal

If there are major or conflicting comments

This will necessitate the development of a second draft and a further round of review. If the comments are conflicting then it is often best to have a teleconference to discuss them and ensure that everyone is in agreement before making any changes. If agreement cannot be reached then the lead author (or the guarantor for the manuscript) should decide what to do.

Depending on the comments on the next draft the cycle will then continue. However, it is important to remember that the manuscript is being written to be published and you should not have innumerable review rounds, demanding perfection if this is at the cost of submitting.

If the message is incorrect, then the document fails…

I have just started perusing The Craft of Editing  by Michael Alley, which is subtitled A guide for managers, scientists, and engineers. Right near the start three different types of editing are highlighted, editing for content, editing for style and editing for form. However, the most important thing emphasized at this point is that whilst a lot of time might be spent discussing editing for style or form, these are relatively unimportant compared with editing for content.

Editing for content is defined as ensuring that the information included is correct, complete, appropriate for the audience, appropriate for the purpose and acceptable for distribution. This is generally managed by a different person to the other types of review as it will often require knowledge of the topic being discussed.

This is extremely important as we might have a beautifully written piece with no grammatical or spelling errors that is completely wrong for its intended use, and does not convey the correct key message, or even worse contains incorrect information and misleads rather than educates. This is very well put in the book where it states:

 If the message is incorrect, then the document fails, no matter how well the message is communicated or what form it is in.

I think this is something we all need to remember as we try to write or edit scientific literature.

In case you want to read this book it can be found on Amazon here: The Craft of Editing: A Guide for Managers, Scientists, and Engineers

What are the four types or reviewing?

In my thinking there are four main types of reviewing:

  • General review for story flow and sense
  • Copy edit
  • Proofread
  • Data check

Each of these is done for a specific reason and aims to potentially identify different issues with a piece of writing. However, they should not be thought of as exclusive activities. We might copy edit to some degree whilst undertaking a general review, or data check whilst proofreading. Nonetheless, it should be noted that if you are asked to do one type of review you should not undertake another without ensuring that the author of the piece is happy for you to do so. It can be distracting, as well as dispiriting, if lots of minor grammatical and spelling errors are pointed out when someone is expecting you to highlight major issues with story.

General review

This will check that the ‘story’ flows well and that everything makes sense. At this stage you will be ensuring that each argument builds upon a previous one and links to it, without anything being missed or detours being taken. To do this it is important that the objective of the piece of writing has been communicated to the reviewer as well as any issues that the author might be aware of that they want the reviewer to concentrate on. In order to provide the most useful review an understanding of what is being discussed is needed.

Copy edit

This is performed to check that sentences flow well and the most appropriate language is used to make it easy to both read and understand. This might include trimming the piece to make it more streamlined.


This should check that spelling and grammar are correct and that the document makes sense. It can also be a final check before publishing to ensure that typeset text is correct and that layout is appropriate.

Data check

This is exactly what you might think and should ensure that all references are appropriate and any data from analyses and study reports have been input correctly

Whilst writing this I was listening to Hyperdub 10.3.