Not just a phase: JBI systematic review protocols

Many reviewers are eager to ‘just get on with the job’ and leap headlong into undertaking a systematic review. For some, the systematic review protocol can seem like a phase to finish as rapidly as possible on the way to where the ‘real’ work takes place in the conduct of the systematic review. It is important to remember that protocols serve important functions; they document and guide review methods, guard against arbitrary decision making and selective reporting, and also help to avoid unnecessary duplication of research effort between review teams. A JBI systematic review protocol must adhere to the same rigorous and exacting standards that a full systematic review report should. Protocols are peer reviewed and receive the same level of editorial scrutiny, and as such should be afforded the same degree of attention and meticulousness. It is critical to ensure that we recognize that protocols are a necessary and indispensable stage of the systematic review process that can frequently save a lot of time, sleep, and headaches later on. In this editorial, I would like to reflect upon the importance of some of the main aspects of the systematic review protocol. The purpose of the background section of the protocol is to cover the main elements of the topic to be reviewed and should present an indication of the existing evidence base of the topic area. The background should provide the reader with sufficient detail regarding how the specific elements of the review's inclusion criteria - the PICO - have been chosen. Reviewers must clearly and definitively explain any concepts or definitions that are important to the review. It is also vital that a statement is included indicating that there are no other current systematic reviews, protocols or registered titles that overlap with the proposed systematic review. Developing inclusion criteria to guide the study selection process within the review demands that reviewers have a reasonable understanding and awareness of the current literature on the topic. In any systematic review protocol, it is essential that all elements of the inclusion criteria are listed along with clear definitions. Poorly thought out, incomplete or ambiguously worded inclusion criteria can be the Achilles heel of a systematic review. As the search strategy is developed on the basis of the inclusion criteria, inadequacies in the inclusion criteria can mean that the search may need to be redesigned and repeated. Furthermore, if the inclusion criteria are ambiguous, or conversely too restrictive, problems may also arise during study selection. When it comes to describing the methods that will be used for the critical appraisal of studies and the extraction and synthesis of data, these sections should provide the reader with an explicit description of the methods that will be adhered to in the conduct of the review. While the JBI SUMARI software does provide reviewers with some useful set text to guide completion of these sections, reviewers must ensure that this text transparently represents the actual approaches that will be followed. For example, reviewers should consider whether their outcome data will be continuous or categorical and ensure that their protocol clearly reflects this. Reviewers can also define in the protocol not only that subgroup analysis will be undertaken if necessary, but also what the expected subgroups will be based upon. This editorial has touched upon some of the basic features of a systematic review protocol that reviewers should focus on. For a detailed examination of how reviewers can improve transparency, accuracy, and completeness when developing protocols, the recent paper by Shamseer and colleagues is an excellent read.1