VU Systematic Literature Reviews: Other review types

Other review types

You need to carefully choose the review type that will match the purpose and scope of your research. It is vital you have a clear understanding of what is involved when undertaking a particular type of review. Follow relevant standards and adhere to best practice methods as outlined in this guide.
 

Scoping review Systematic review Narrative (literature) review

What is it?

 Aims to provide an overview or map of the available evidence, focusing on concepts, themes and types. Conducted according to similar rigorous and transparent methods as systematic reviews, but typically answers broad questions and does not require critical appraisal. Attempts to identify, appraise and synthesise all empirical evidence that meets pre-specified eligibility criteria to answer a given research question. Uses explicit, reproducible methods aimed at minimising bias, to produce reliable findings and inform decision making. Synthesises the findings of literature retrieved from searches of computerised databases, hand searches, and authoritative texts.
Why do it? To capture breadth instead of depth of literature; identify gaps within the research area; occasionally used as a precursor to a systematic review. To address a clearly focused review question by finding the best available, relevant research studies and synthesising the results. To set the scene for the research, often as part of a bigger project/thesis. 
Question Often broad e.g. trying to find out what is already known about a topic. However, there is also scope to have a pre-conceived question to assess what literature is available around the subject. Focused on a single topic. May start with a clear question to be answered, but they more often involve general discussion of a subject with no stated hypothesis; i.e. a topical approach.
Sources / search Ideally, a protocol or plan is included. Clear objectives are identified. Comprehensive sources and explicit and reproducible search strategy. Use of a wide range of resources, including black and grey literature, of any study type.

A peer reviewed protocol or plan is included. Clear objectives are identified. Comprehensive sources and explicit and reproducible search strategy.

Use of a wide range of resources, including black and grey literature. Often a focus on randomised controlled trials.

 Does not attempt to locate all relevant literature in a systematic, reproducible way. Search strategy, if presented, may be described in broad terms.
Eligibility criteria

Eligibility criteria are clearly defined before the review is conducted but may be revisited throughout the review. Due to the iterative nature of a scoping review, some changes may be necessary.

 Eligibility criteria are clearly defined before the review is conducted. Not usually used or applied as database limits.
Selection / screening Often broad - may differ depending on resources found. Criterion-based selection is uniformly applied, clear and explicit. Criterion-based selection is uniformly applied, clear and explicit. Not specified, or ad hoc. 
Appraisal Variable - typically not done, or done in narrative form. Rigorous critical appraisal, and evaluation of study quality. Expected to demonstrate a critical approach to interpretation of research findings but not done in a systematic, reproducible manner.
Synthesis Depends on the purpose, using a descriptive summary (tabulation is optional). Clear summaries of studies based on high quality evidence. May include a meta-analysis. Often descriptive summary.
Inferences Evidence-based. Evidence-based. Subjective, possibly evidence-based.

Acknowledgements: Dr Maureen McEvoy, Dr Steven Milanese, Dr Saravana Kumar, and Dr Craig Phillips, University of South Australia.

Guidelines and standards

Further resources