Systematic Reviews in the Health Sciences: Other Review Types
Should you consider another type of review?
Not all reviews are, or should be, systematic reviews. The following article offers a typology of different review types you may want to consider (see Table 1 for brief descriptions):
Grant M, Booth A. A typology of reviews: an analysis of 14 review types and associated methodologies. Health Information & Libraries Journal. 2009;26(2):91-108.
Some alternatives you might want to consider, depending on your time, scope, and resources, include:
Systematic Search and Review / Systematized Review
See the Grant and Booth article above for full description. These tend to fall short of full systematic review. There may or may not be a fully comprehensive search, and the review may take a narrative rather than a quality assessment approach. Often these are done as course assignments, where the reviewers lack the time and resources to do a full systematic review.
Purpose: To utilize the methods of systematic reviewing in a shorter timeframe to generate an immediate answer to an urgent or emerging topic. Rapid reviews make take three weeks to six months, as opposed to 18 months and up for a rigorous systematic review. They tend to be restricted to more easily-retrievable evidence; as a result, they sacrifice some of the rigour of a full systematic review.
How to do it:
- Ganann R, Ciliska D, Thomas H. Expediting systematic reviews: methods and implications of rapid reviews. Implementation Science. 2010;5(1):56.
- Khangura S, Polisena J, Clifford T, Farrah K, Kamel C. Rapid review: an emerging approach to evidence synthesis in health technology assessment. International Journal of Technology Assessment in Health Care. 2014;30(01):20-27.
- Canadian Agency for Drugs and Technologies in Health (CADTH). Rapid Review Summit. 2015
Example: Hersi M, Stevens A, Quach P, Hamel C, Thavorn K, Garritty C et al. Effectiveness of Personal Protective Equipment for Healthcare Workers Caring for Patients with Filovirus Disease: A Rapid Review. PLOS ONE. 2015;10(10):e0140290.
Purpose: To assess the size and scope of available research literature, and identify gaps and research needs. The extent of the literature search depends on the reviewers time/scope constraints. While the quality of existing evidence may be described, there is usually not a formal quality appraisal process as with a systematic review.
How to do it:
- Arksey H, O’Malley L. Scoping studies: towards a methodological framework. International Journal of Social Research Methodology 2005 8;1:19-32.
- Colquhoun HL, Levac D, O'Brien KK, Straus S, Tricco AC, Perrier L, Kastner M, Moher D. Scoping reviews: time for clarity in definition, methods, and reporting. Journal of Clinical Epidemiology. 2014 Dec;67(12):1291-4.
BMC Medical Research Methodology. 2013 Mar 23;13:48.
Daudt HM, van Mossel C, Scott SJ. Enhancing the scoping study methodology: a large, inter-professional team's experience with Arksey and O'Malley's framework.
- Khalil H, Peters M, Godfrey C, McInerney P, Soares C, Parker D. An Evidence-Based Approach to Scoping Reviews. Worldviews on Evidence-Based Nursing. 2016;13(2):118-123.
Levac D, Colquhoun H, O'Brien KK. Scoping studies: advancing the methodology. Implement Science. 2010 Sep 20;5:69.
Example: Shommu N, Ahmed S, Rumana N, Barron G, McBrien K, Turin T. What is the scope of improving immigrant and ethnic minority healthcare using community navigators: A systematic scoping review. International Journal for Equity in Health. 2016;15(1).
Umbrella Review (Review of Reviews)
Purpose: To synthesize the findings of several reviews around the same question. Quality appraisal may be of the reviews themselves, or of the studies contained within them.
How to do it:
- McKenzie J. and Brennan, S. Overviews of systematic reviews: great promise, greater challenge. Systematic Reviews. 2017; 6(185).
- Ioannidis J. Integration of evidence from multiple meta-analyses: a primer on umbrella reviews, treatment networks and multiple treatments meta-analyses. Canadian Medical Association Journal. 2009;181(8):488-493.
- Pham M, Rajić A, Greig J, Sargeant J, Papadopoulos A, McEwen S. A scoping review of scoping reviews: advancing the approach and enhancing the consistency. Research Synthesis Methods. 2014;5(4):371-385.
Example: Lau R, Stevenson F, Ong B, Dziedzic K, Treweek S, Eldridge S et al. Achieving change in primary care—effectiveness of strategies for improving implementation of complex interventions: systematic review of reviews. BMJ Open. 2015;5(12):e009993.
Purpose: To situate the evidence in the context in which it is being applied - realizes that context influences the outcomes of an intervention. Often summed up as "what works, how, for whom, in what circumstances and to what extent?" (Greenhalgh et al., 2011).
How to do it:
- Kirst M, O'Campo P. Realist Review and Evaluation: What Do We Know about What Works?. In: Burke J, Steven A, ed. by. Methods for Community Public Health Research: Integrated and Engaged Approaches. 1st ed. New York: Springer; 2014.
- Pawson R, Greenhalgh T, Harvey G, Walshe K. Realist review - a new method of systematic review designed for complex policy interventions. Journal of Health Services Research & Policy. 2005;10(suppl 1):21-34.
- Wong G, Greenhalgh T, Westhorp G, Buckingham J, Pawson R. RAMESES publication standards: realist syntheses. Journal of Advanced Nursing 69(5), 1005-1022.
Smylie J, Kirst M, McShane K, Firestone M, Wolfe S, O'Campo P. Understanding the role of Indigenous community participation in Indigenous prenatal and infant-toddler health promotion programs in Canada: A realist review. Social Science & Medicine. 2016;150:128-143.