2Planning Your Review The Review Protocol What is the role of the review protocol?Why is a review protocol necessary?What information does it contain?
3Role of the ProtocolThe protocol is the first milestone of any systematic reviewA (rigid) plan or framework for the reviewA protocol helps to avoid or minimise biasBias may occur in the retrieval, selection, and appraisal of studies, as well as during the extraction, evaluation and interpretation of dataA protocol can (and should be) sent for external peer review
5Background sectionSets the context and provides the rationale for the review:Patients / disease characteristics, e.g. epidemiologyImportance: clinical and public health implicationsCurrent practiceAlternative interventionsAvailable evidence, including existing systematic reviews
6Research questions/ objectives Precise formulation in relation to key components (PICO):Population/ patients / problemIntervention, or exposureComparison groupOutcome(s) of interest
7Search StrategyThe protocol should make it clear how relevant studies are going to be identified:Specify which databases (including dates) and other sources will be searchedIdentify key search terms
8Study SelectionThe protocol should make it clear how studies will be selected for inclusion in the review:Specify the inclusion (and exclusion) criteriaReport details of selection processHow many reviewers involved?Will the process be completed independently?How will disagreements be resolved?
9Quality AssessmentThe protocol should make it clear why and how included studies will be quality assessed:State the purpose of quality assessment, e.g. is it for selection, data synthesis, interpretation of results?Describe the criteria / checklist to be usedDetail the quality assessment process / procedureHow many reviewers involved?Will the process be completed independently?How will disagreements be resolved?
10Data Extraction The protocol should report: What data are to be extracted from primary studiesA draft template for data extractionHow data will be presented in the reportAny planned manipulations of study data, e.g. calculation of summary statistics, ITT-analysis, etc.The process of data extractionHow many reviewers will be involved?How will disagreements be resolved?
11Data SynthesisThe protocol should identify and justify indicate and justify the:Data that are to be tabulatedPotential sources of heterogeneity to be investigated, e.g. subgroup analysisMethod of synthesisAny proposed sensitivity analysesIn HBI reviews it may not be possible to be too specific at protocol stage, but these issues need a priori consideration
12DisseminationFailing to disseminate research findings is unethical, and the protocol should detail precisely a dissemination strategy:How will you disseminate the findings?Where will you publish?How will you publish your review?In what format will you publish?Who is your intended audience?
13Peer review / Advisory Group Reviewers should establish an Advisory Group who can provide peer-review at different stages of the review processTopic experts (including ‘users’) will be able to comment on the relevance of the review question, as well as possible sources of heterogeneityMethodological experts will be able to comment on whether the proposed methods will answer the review questionsTrainees must obtain protocol approval before starting their SR