Evidence based practice - an introduction is a library guide produced by the Library for undergraduates. The information contained in the guide is also relevant for post graduate study and will help you to understand the types of research and levels of evidence required to conduct evidence based research.
Researchers, academics and librarians all use various terms to describe different types of literature reviews. Indeed there is often inconsistency between the ways the types are discussed. Here are a couple of simple explanations.
The image below describes common review types in terms of speed, detail, risk of bias and comprehensiveness:
"Schematic of the main differences between the types of literature review" by Brennan, M. L., Arlt, S. P., Belshaw, Z., Buckley, L., Corah, L., Doit, H., Fajt, V. R., Grindlay, D., Moberly, H. K., Morrow, L. D., Stavisky, J., & White, C. (2020). Critically Appraised Topics (CATs) in veterinary medicine: Applying evidence in clinical practice. Frontiers in Veterinary Science, 7, 314. https://doi.org/10.3389/fvets.2020.00314 is licensed under CC BY 3.0
The table below has been adapted from a widely used typology of fourteen types of reviews, (Grant & Booth, 2009). Here are four of the most common types:
|REVIEW TYPES||DESCRIPTION||APPROXIMATE TIMEFRAME||NO. OF REVIEWERS|
|Systematic review||Seeks to systematically search for, appraise and synthesise research evidence in order to aid decision-making and determine best practice. Systematic reviews can vary in their approach, and are often specific to the type of study: studies of effectiveness, qualitative research, economic evaluation, prevalence, aetiology or risk, diagnostic test accuracy and so on.||8 months to 2 years||2 or more|
|Rapid review||Assesses what is known about an issue by using a systematic review method to search and appraise research and determine best practice.||2-6 months||2|
|Scoping review||Assesses the potential scope of the research literature on a particular topic. Helps determine gaps in the research.||2-8 weeks||1-2|
|Traditional (narrative) literature review||A generic review which identifies and reviews published literature on a topic, which may be broad. Typically employs a narrative approach to reporting the review findings. Can include a wide range of related subjects.||1-4 weeks||1|
For a more detailed list of review types, see:
Grant, M.J. & Booth, A. (2009). A typology of reviews: An analysis of 14 review types and associated methodologies. Health Information & Libraries Journal, 26(2), 91-108. DOI: 10.1111/j.1471-1842.2009.00848.x
See also our Library Resource Guide, Literature Review.
A systematic literature review (SLR) identifies, selects and critically appraises research in order to answer a clearly formulated question (Dewey, A. & Drahota, A. 2016). The systematic review should follow a clearly defined protocol or plan where the criteria is clearly stated before the review is conducted. It is a comprehensive, transparent search conducted over multiple databases and grey literature that can be replicated and reproduced by other researchers. It involves planning a well thought out search strategy which has a specific focus or answers a defined question. The review identifies the type of information searched, critiqued and reported within known timeframes. The search terms, search strategies (including database names, platforms, dates of search) and limits all need to be included in the review.
Pittway (2008) outlines seven key principles behind systematic literature reviews
Systematic literature reviews originated in medicine and are linked to evidence based practice. According to Grant & Booth (p 91, 2009) "the expansion in evidence-based practice has lead to an increasing variety of review types". They compare and contrast 14 review types, listing the strengths and weaknesses of each review.
Tranfield et al (2003) discusses the origins of the evidence-based approach to undertaking a literature review and its application to other disciplines including management and science.
References and additional resources
Dewey, A. & Drahota, A. (2016) Introduction to systematic reviews: online learning module Cochrane Training http://training.cochrane.org/path/introduction-systematic-reviews-pathway/1
Gough, David A., David Gough, Sandy Oliver, and James Thomas. An Introduction to Systematic Reviews. Systematic Reviews. London: SAGE, 2012.
Grant, M. J. & Booth, A. (2009) A typology of reviews: An analysis of 14 review types and associated methodologies. Health Information & Libraries Journal 26(2), 91-108
Pittway, L. (2008) Systematic literature reviews. In Thorpe, R. & Holt, R. The SAGE dictionary of qualitative management research. SAGE Publications Ltd doi:10.4135/9780857020109
Tranfield, D., Denyer, D & Smart, P. (2003) Towards a methodology for developing evidence-informed management knowledge by means of systematic review. British Journal of Management 14(3), 207-222