Library: Systematic reviews: Write a protocol

What is a protocol?

The protocol is a published plan that describes the objectives and methods you will follow for your review.

A good protocol will ensure that your review will go smoothly. It should be built on a sound research question, with strict inclusion/exclusion criteria, and firm ideas about data extraction and quality assessment.
During the drafting of the protocol, you will be developing your research question and testing your search strategy in one database, including choosing the keywords to use and which studies to include or exclude. The frameworks described in Formulate your question, including PICO, may help you develop your research question and search strategy.
It is important that you confirm that your review has not been done before, by checking the registers of completed or in-progress reviews.
It is recommended that you register your own finalised protocol, so that other researchers are made aware of your review and you are able to cite it.

Looking for protocols

Before you write your protocol and to ensure the uniqueness of your review, you should search the registers of completed and ongoing studies. Below, are some suggested starting-points for your searches.

ClinicalTrials.gov
A registry of clinical trials conducted in the US or other countries, it is provided by the National Library of Medicine.
International Clinical Trials Registry Platform
Created by the World Health Organization, the ICTRP enables a search across a range of registers from around the world.
Cochrane Database of Systematic Reviews (CDSR)
CDSR contains full text systematic reviews prepared by the Cochrane Collaboration. Reviews are of two types: full reviews (Cochrane Reviews) and protocols (in-progress reviews).

Writing a protocol

When designing your protocol, refer to the reporting guidance for your type of review, to ensure that you do not forgot to include something in the initial stages that you are expected to report at the end. The following resources may also be of help:

PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses)
PRISMA stands for Preferred Reporting Items for Systematic Reviews and Meta-Analyses. It is designed to guide the recording of methods and results in systematic reviews. PRISMA is used for different types of systematic review (and commonly for reviews of randomised trials).
Protocol Development for Systematic Reviews
Guidance (provided by Covidence) on the registering and writing of protocols. Processes covered include objectives, search strategy, eligibility criteria and methods. TO ACCESS THE BOOK, you need to register your details via the above link.

Registering your protocol

It is recommended that you add your final protocol to a register to raise awareness among researchers. PROSPERO is just one register you might want to consider:

PROSPERO
Register of human research protocols
Campbell Systematic Reviews
Social, economic and healthcare topics.

Cochrane Library This link opens in a new window
A collection of databases that contain high-quality, independent evidence to inform healthcare decision-making, including systematic reviews.

EPPI-Centre
Broad coverage of social and health topics
Joanna Briggs Institute
Evidence database supporting healthcare delivery.

Inclusion/exclusion criteria

The Library of the University of Melbourne provides a helpful infographic about common inclusion or exclusion criteria.

More advice about writing a protocol

Module 2 in Cochrane Interactive Learning provides advice about the key components and structure of a protocol. The Library is subscribing to Cochrane Interactive Learning.