Pro tip: If you already have some relevant articles, review them to develop your data extraction strategy. What data will you need to extract to answer your question?
A document that "describes the rationale, hypothesis, and planned methods of the review. It should be prepared before a review is started and used as a guide to carry out the review." - PRISMA protocol guidelines
A 2018 study identified an association between registration of a protocol in PROSPERO and the overall review quality of its systematic review based on the AMSTAR tool. The authors speculated that the time spent planning and documenting all of the review procedures might indirectly result in more robust methods. But regardless of where you register, completing a protocol is time well invested.
Review the checklist for the PRISMA-P protocol guidelines or the PROSPERO registration form. Can you complete all the applicable items? If so, you may be ready to register. You will be expected to stick to your protocol just as if it were a lab protocol, so make sure you have documented the process you intend to follow.
Prepare to answer the following:
Here are some of the standard protocol templates. If you are conducting a review according to a specific standard, you must use that standard's protocol guidelines. If you are not writing to a specific standard, you may still use a standard's guidelines if they are appropriate to your topic, or use PRISMA-P.
If any of the elements are confusing or you're not sure how to do them, you can schedule with a librarian to discuss it further.
From your research question development, your protocol can include detailed elements of intent. Being as specific as possible, this is another way to mention some of the strengths and weaknesses within current research and highlight aspects of the health and social gradient that need to be addressed. Examples of elements to include are the following:
This may seem like a lot of work and very detailed, but even the mention of these elements is very crucial to addressing much larger issues within research and this is a way you can play a role in combatting inequities in medical and health research.
Where you register your protocol depends partially on your type of review and your topic. Here are some of the options.
Should I use PROSPERO or PRISMA-P for a systematic review?
They serve different purposes: PROSPERO specifies its required fields for registering your review, but doesn't go into a lot of detail about the content. PRISMA-P provides more guidance on the content, but is not a place to register your review. You can use the information in PRISMA-P to help you write your PROSPERO entries.