Hi all, welcome back! Hope you have read and enjoyed the previous blog on “How to do a systematic review-10 simple steps for beginners.” In case you missed it, you can still go back and read it.
We are moving to the details of each step involved in a review. Now that you have decided your amazing topic and formulated the research question, it’s time to write down your review protocol. You can get detailed information on PRISMA website (PRISMA Link: http://prisma-statement.org/Protocols/ProtocolGuidance). But as promised I have simplified the steps which you should follow in writing your review protocol. So, let’s dive in.
Make sure that the title of your review should include the word ‘systematic review’ in it. It helps in identifying the article as a systematic review instantly. E.g., the title of my review was “Effect of TENS on spasticity in adults with stroke; A systematic review and meta-analysis.”
- Authors and their contribution:
Before you begin the review or you are at the protocol stage, you should be sure of your team members and how they are going to contribute to it. Divide the work initially for smooth and hassle-free completion of the review. E.g., Author 1 and 2 will screen and extract the data. Author 3 will conduct the meta-analysis or risk of bias; Author 4 will be contacted in case of disagreement, etc.
Mention the name of your funders or sponsors if you have got support for conducting the review.
- Introduction – rationale and objective:
Prepare a brief introduction for your review with emphasis on the need for conducting the review. Why this review was required, what is already known and what do you wish to know through this review. Is there no evidence or conflicting evidence on that particular topic? Remember that the need should be convincing enough for the readers and editors of course!
As I explained in the last post, you should discuss your methods with your supervisor or senior colleague because it determines the quality of your review. Write down the eligibility criteria, PICO format, study design, setting, time frame, years considered, language, and publication status for including the studies. Also, mention the databases which you planned to search. Whether or not you wish to include grey literature. It is a good idea to prepare the search strategy of at least one database and write it in the protocol.
- Data extraction:
Give a clear picture of how the data extraction will be done. Will you develop and pilot test the extraction sheet or will you use an existing one? It is always better to adapt the data extraction sheet from an existing one which suits your study requirement. We will discuss further on it later.
It is the heart of your review. Mention about all the outcomes which you wish to extract and analyze in the study. Which outcomes do you want to exclude and why?
- Critical appraisal/risk of bias analysis:
This is again a critical and unique component of a systematic review. You will have to write down how will you analyze the included studies or how will you do the risk of bias. Mention the scale or tool which you will use for appraising the article.
- Data Synthesis
Give details on how you will summarize the included studies, i.e., narratively or quantitatively. Ideally, you should do both. Qualitative synthesis would consist of the way you wish to present your data. E.g., an effect of a treatment alone or effect of treatment as an adjunct, or effect in the chronic or acute stage, etc. Details on quantitative synthesis/meta-analysis would include describing the summary measures, subgroup analysis and heterogeneity in the data.
- GRADE your review:
You may also wish to do GRADE (Grading of Recommendations Assessment, Development, and Evaluation) to rate the quality of evidence and develop recommendations in guidelines. More info on http://www.gradeworkinggroup.org/
So, these were some core features which you should mention in your protocol. It would not only help you in building your review of good quality, but it will also help you in planning ahead. A good idea is to keep a timetable for completing the review, right from screening the articles to preparing the manuscript. Otherwise, it may get excessively delayed (don’t ask me how much time I took to complete mine. Once you have written the protocol, register it in PROSPERO, and you are good to go! Best of luck 🙂
- ShamseerL, Moher D, Clarke M, Ghersi D, Liberati A, Petticrew M, Shekelle P, Stewart L, RISMA-P Group. Preferred reporting items for systematic review and meta-analysis protocols (PRISMA-P) 2015: elaboration and explanation. BMJ. 2015Jan 2;349(jan02 1):g7647.