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Systematic Reviews

This guide describes all steps involved in the conduct of a systematic review

Types of Reviews

All review types should be ‘systematic’. Meaning all the research is expected to follow some ‘system’. Commonly the methods used must be reproducible and transparent Sutton et al., 2019. 

It is important to understand that the (research) question you want to answer correlates with the type of review you want to write. Each review type has its own design and objective, which for example depends on the objective, evidence type, audience and planning. For this reason, it is always important to have a clearly defined and searchable question. 

The table gives an overview of different review types characterized according to framework by Grant et al., 2009. 

Common types of systematic reviews

Type of Review Description Limitations Guideline How to?
Systematic search and review Combines strengths of critical review with exhaustive search process. Addresses broad questions to produce ‘best evidence synthesis’ Narrowly defined review questions provide specific answers to specific questions. Alternative questions that have not been answered usually need to be reconstructed by the reader


Cochrane (Handbook)

Page et al., 2021
Scoping review Identifies nature and extent of research evidence (including ongoing research) Requires multiple structured searches instead of one. Increased emphasis for hand searching the literature.  May require larger teams because of larger volume of literature 


Tricco et al., 2018

Munn et al., 2018

Literature (Narrative) review Examines recent or current literature. Can cover wide range of subjects at various levels of completeness and exhaustively. May include research findings Biases that occur in selecting and assessing the literature are unknown. Cannot be replicated PRISMA-S Rethlefsen et al., 2021
Evidence Synthesis/Map, Mapping review Maps out and categorises existing evidence from which to commission further reviews and/or primary research by identifying gaps in research Broad nature and rapid search may mean that some evidence could be missed Not Present White et al., 2020
Mixed Methods Combines methods that include review components (usually systematic). Specifically combines review approaches such as quantitative with qualitative research or outcome with process studies Involves multiple syntheses and (at least) two main study types. May result in a larger number of citations. May require more search time to create multiple searches for varying outcomes GRAMMS


Thurston et al. 2021
Realist synthesis Synthesises large and diverse selection of literature to inform policy revision, design effective interventions and identity potentially effective and innovative interventions

It is iterative, complex, laborious, and ensuring standardization and reproducibility is difficult 

Quality assurance is dependent on the reviewers' explicitness and reflexivity. Requires a high level of expertise in reasoning, research methods and quality appraisal, and expertise in the subject area

RAMESES Rycroft-Malone et al. 2012