InfoGuides: Systematic Reviews: Explore Types of Systematic Reviews

Systematic Reviews

How is a Systematic Review different from a Literature Review?

"This type of review is a specific methodology that aims to comprehensively identify all relevant studies on a specific topic, and to select appropriate studies based on explicit criteria. In addition, the methodological quality of the studies included is assessed by on the basis of explicit criteria, such as the presence of a pre-test or a control group. In contrast to a conventional literature review, a systematic review (SR) is transparent, verifiable, and reproducible, and, as a result, the likelihood of bias is considerably smaller." Center for Evidence Based Management, https://www.cebma.org/faq/what-is-a-systematic-review/

For information on how to write a literature review:
Efron, S. E., & Ravid, R. (2019). Writing the literature review : a practical guide . The Guilford Press.

	Systematic review	Literature review
Question	Focused on a single question	Not necessarily focused on a single question, but may describe an overview
Protocol	A peer review protocol or plan is included	No protocol is included
Background	Both provide summaries of the available literature on a topic
Objectives	Clear objectives are identified	Objectives may or may not be identified
Inclusion and exclusion criteria	Criteria stated before the review is conducted	Criteria not specified
Search strategy	Comprehensive search conducted in a systematic way	Strategy not explicitly stated
Process of selecting articles	Usually clear and explicit	Not described in a literature review
Process of evaluating articles	Comprehensive evaluation of study quality	Evaluation of study quality may or may not be included
Process of extracting relevant information	Usually clear and specific	Not clear or explicit
Results and data synthesis	Clear summaries of studies based on high quality evidence	Summary based on studies where the quality of the articles may not be expected. May also be influenced by the reviewer's theories, needs and beliefs
Discussion	Written by an expert or group of experts with a detailed and well grounded knowledge of the issues

From : https://libguides.newcastle.edu.au/sysreviews

Scoping reviews follow the same procedures of a systematic review, except:

Answers broader questions beyond those related to the effectiveness of treatments or interventions
Critical appraisal or Risk of Bias assessment is optional
May involve multiple structured searches
Data extracted is charted

	Scoping review	Systematic review
Research question	Broadly defined	Highly focused
Inclusion/Exclusion criteria	Developed post hoc at study selection stage	Developed at protocol stage
Study selection	All study types	Defined study types
Data extraction	“Charts” data according to key issues, themes, etc.	Synthesizes & aggregates findings

From https://guides.library.utoronto.ca/systematicreviews

Peters M, Godfrey C, Khalil H, et al. Guidance for Conducting Systematic Scoping Reviews. Int J Evid Based Healthc. 2015;13:141-146

The Joanna Briggs Institute Reviewers' Manual 2015: Methodology for JBI Scoping Reviews

PRISMA for Scoping Reviews

"Rapid reviews are a form of knowledge synthesis in which components of the systematic review process are simplified or omitted to produce information in a timely manner. " https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4574114/

From https://guides.mclibrary.duke.edu/sysreview

Rapid review

Assessment of what is already known about a policy or practice issue, by using systematic review methods to search and critically appraise existing research.

Completeness of searching determined by time constraints.

Time-limited formal quality assessment.

Typically narrative and tabular.

Quantities of literature and overall quality/direction of effect of literature.

Dobbins, Maureen. Rapid Review Guidebook. Steps for Conducting a Rapid Review. National Collaborating Centre for Methods and Tools, 2017.

"Meta-analysis is the quantitative, scientific synthesis of research results." Gurevitch, J., Koricheva, J., Nakagawa, S., & Stewart, G. (2018). Meta-analysis and the science of research synthesis. Nature, 555(7695), 175–182. https://doi.org/10.1038/nature25753

From https://guides.mclibrary.duke.edu/sysreview

Meta-analysis

Technique that statistically combines the results of quantitative studies to provide a more precise effect of the results.

Aims for exhaustive searching. May use funnel plot to assess completeness.

Quality assessment may determine inclusion/exclusion and/or sensitivity analyses.

Graphical and tabular with narrative commentary.

Numerical analysis of measures of effect assuming absence of heterogeneity.

Shorten A., Shorten B. What is meta-analysis? Evidence-Based Nursing 2013;16:3-4.

Meta-synthesis is a systematic approach to the analysis of data across qualitative studies. -- EJ Erwin, MJ Brotherson, JA Summers. Understanding Qualitative Meta-synthesis. Issues and Opportunities in Early Childhood Intervention Research, 33(3) 186-200.

Why use a meta-synthesis?

Qualitative data is useful for providing a snapshot at one person’s interpretation of an event or phenomenon. By bringing together many different interpretations you are strengthening the evidence for an interpretation by discovering common themes and differences & building new interpretations of the topic of interest. https://abbarker.wordpress.com/2013/04/25/meta-synthesis/

Finlayson KW, & Dixon A. (2008). Qualitative meta-synthesis: a guide for the novice. Nurse Researcher, 15(2), 59–71.

Kent B, & Fineout-Overholt E. (2008). Using meta-synthesis to facilitate evidence-based practice. Worldviews on Evidence-Based Nursing, 5(3), 160–162.