A systematic review should start with a peer-reviewed protocol, or plan. The protocol describes the rationale, the objectives, and the methods that will be used to locate, select and critically appraise studies, and to collect and analyze data from the included studies. The Institute of Medicine's Standards for Initiating a Systematic Review (Standards 2.7 and 2.8) recommends that you publish your protocol in order to prevent author bias and to allow feedback at an early stage in the review. Publishing your review helps ensure the quality of the review as well as avoiding unnecessary duplication of effort. Registries for publishing your protocol are listed below.
PROSPERO was started in 2011 by the Centre for Reviews and Dissemination (CRD) at the University of York, and is an open access, prospective international systematic review register. It includes protocols of systematic reviews relevant to health and social care, welfare, public health, education, crime, justice, and international development, where there is a health related outcome. The Guidance notes for registering a systematic review protocol with PROSPERO, CRD, 2016, can be used when preparing a research protocol.
The Cochrane Collaboration's mission is to provide accessible, credible information to support informed decision making. Contributors are affiliated to the organization through Cochrane Review Groups; you should register your interest in writing a review with the appropriate review group. Box II.1.a from the Cochrane Handbook for Systematic Reviews of Interventions lists the sections of a protocol for a Cochrane review.
The Campbell Collaboration is an international research network that produces systematic reviews of the effects of social interventions in crime and justice, education, international development, and social welfare. Online resources and tools are available at the Campbell Collaboration Resource Center.
The following table of required elements from the IOM's Standards for Initiating a Systematic Review (Standard 2.6) provides a checklist for the content of a systematic review protocol:
|2.6.1||Describe the context and rationale for the review from both a decision-making and research perspective|
|2.6.2||Describe the study screening and selection criteria (inclusion/exclusion criteria)|
|2.6.3||Describe precisely which outcome measures, time points, interventions, and comparison groups will be addressed|
|2.6.4||Describe the search strategy for identifying relevant evidence|
|2.6.5||Describe the procedures for study selection|
|2.6.6||Describe the data extraction strategy|
|2.6.7||Describe the process for identifying and resolving disagreement between researchers in study selection and data extraction decisions|
|2.6.8||Describe the approach to critically appraising individual studies|
|2.6.9||Describe the method for evaluating the body of evidence, including the quantitative and qualitative synthesis strategy|
|2.6.10||Describe and justify any planned analyses of differential treatment effects according to patient subgroups, how an intervention is delivered, or how an outcome is measured|
|2.6.11||Describe the proposed timetable for conducting the review|