Systematic and Other Reviews: Preparing a Protocol

Preparing a protocol

A protocol is a plan that shows how you will conduct your review. It needs to be written and lodged before you begin your review. It is a living document which can be updated throughout the course of your review, and any changes you make are on the public record. 

Before lodging your protocol, make sure it includes: 

• Research questions and aims of the review;
• Your PICO breakdown (if relevant);
• Your eligibility criteria (inclusion and exclusion);
• Where you will search (databases and grey literature);
• How you will:
  • screen your records
  • extract and manage the data
  • assess bias
  • analyse data

Standards and manuals like PRISMA-P (for quantitative reviews) or JBI (for qualitative reviews) describe the necessary elements that need to be included for your protocol to have sufficient detail.

See below for a list of checklists and guidelines.

• PRISMA-P (2020) - quantitative reviews
• PROSPERO - various review types, including qualitative and quantitative
• JBI Manual for Evidence Synthesis - Chapter 2.6 (Protocols for Qualitative Reviews)
• Cochrane’s MECIR - quantitative and qualitative reviews
• Campbell Collaboration's MECCIR - quantitative and qualitative reviews (see section under Methodological Expectations of Campbell Collaboration Intervention Reviews)

Inclusion and exclusion criteria

Your protocol will prompt you to state what study designs and characteristics must be included or excluded from your review. This step clarifies the scope of your review, and ensures the data is sufficiently "alike" to perform analysis or synthesis.

This criteria is very important during the screening stage. If your criteria is not detailed enough, you may need to spend more time later establishing consensus among your reviewers about what to include or exclude. 

See below for an example.

Where to search

A systematic review aims to find every possible piece of evidence, resulting in a thorough list of searching locations and techniques.

Consider the following searching methods for inclusion in your review and protocol:

Bibliographic databases (Health)

A comprehensive search in the health discipline includes the following database selections:

• Medline (Ovid) and Embase should always be included,
• Large health databases such as CINAHL, PsycINFO, Cochrane Library, JBI EBP, Proquest Health and Medicine as appropriate, 
• Discipline specific databases such as AMED, PEDro, SPORTDiscus, APA PsycARTICLES, Maternity and Infant Care (MIC) as appropriate;
• One multidisciplinary database to overcome discipline bias; Scopus, Web of Science (All databases), Proquest Central.

Hand Searching

All systematic review should include hand searching. This is covered in later sections.

Grey Literature

Some review questions are best answered with the addition of conference papers, reports, theses and more. Grey literature and searching methods are covered in later sections.

Lodging a Protocol 

There are two main registries for systematic review protocols:

Chapter Summary