A systematic review is a summary of the medical literature that uses explicit methods to perform a comprehensive literature search and critical appraisal of individual studies and that uses appropriate statistical techniques to combine these valid studies. (CEBM).
Key characteristics of a systematic review are:
Meta-analysis is a systematic review process that uses quantitative methods to synthesize and summarize the results.
Meta-synthesis is a systematic review process that synthesises a number of qualitative studies to reveal new understandings
Jahan, N., Naveed, S., Zeshan, M., & Tahir, M. A. (2016). How to conduct a systematic review: A narrative literature review. Cureus, 8(11), e864. doi:10.7759/cureus.864
Shamseer, L., & Moher, D. (2015). Planning a systematic review? Think protocols. Retrieved from BioMed Central blog:https://blogs.biomedcentral.com/bmcblog/2015/01/05/planning-a-systematic-review-think-protocols/
JBI Manual for Evidence Synthesis
Cochrane Handbook for Systematic Reviews of Interventions
The Equator Network develops and provides Reporting Guidelines for all types of studies
The Collaboration for Environmental Evidence (CEE) has developed a set of standards and methods specifically for reviews on environmental issues.
Scoping review – an overview of a broad field; can show research gaps. Can be an ideal first review for any research project.
JBI Manual for Evidence Synthesis. Chapter 11: Scoping reviews
Peters, M. D., Godfrey, C. M., Khalil, H., McInerney, P., Parker, D., & Soares, C. B. (2015). Guidance for conducting systematic scoping reviews. International Journal of Evidence-Based Healthcare, 13(3), 141-146. doi:10.1097/XEB.0000000000000050
Tricco, A. C., Lillie, E., Zarin, W., O'Brien, K. K., Colquhoun, H., Levac, D., . . . Straus, S. E. (2018). PRISMA Extension for Scoping Reviews (PRISMA-ScR): Checklist and explanation. Annals of Internal Medicine, 169(7), 467-473. doi:10.7326/M18-0850
Tricco, A. C., Lillie, E., Zarin, W., O'Brien, K., Colquhoun, H., Kastner, M., . . . Straus, S. E. (2016). A scoping review on the conduct and reporting of scoping reviews. BMC Medical Research Methodology, 16, 15. doi:10.1186/s12874-016-0116-4
Colquhoun, H. (2016 May). Current best practice for the conduct of scoping reviews, (Powerpoint slides) Presented at Impactful Biomedical Research: Achieving Quality and Transparency. Available from: http://www.equator-network.org/wp-content/uploads/2016/06/Gerstein-Library-scoping-reviews_May-12.pdf
Arksey, H., & O'Malley, L. (2005). Scoping studies: Towards a methodological framework. International Journal of Social Research Methodology, 8(1), 19-32. doi:10.1080/1364557032000119616
Integrative review – the only approach that allows for the combination of diverse methodologies (for example, experimental and non‐experimental research). Useful in nursing research when qualitative and quantitave approaches have to be evaluated.
Whittemore, R & Knafl, K. (2005). The integrative review: updated methodology. Journal of Clinical Nursing, 52(5), 646-53. doi: 10.1111/j.1365-2648.2005.03621.x
Protocol – a stated intention to perform a review; detailing purpose, methods, search strategies, databases and exclusion criteria.
Register the protocol with PROSPERO https://www.crd.york.ac.uk/PROSPERO/
Use PRISMA-P guidelines to develop the protocol
Shamseer, L., Moher, D., Clarke, M., Ghersi, D., Liberati, A., Petticrew, M., . . . Group, P.-P. (2015). Preferred reporting items for systematic review and meta-analysis protocols (PRISMA-P) 2015: elaboration and explanation. BMJ, 349, g7647. doi:10.1136/bmj.g7647
Rapid review – when there is not the time to execute a full SR; but without compromising quality
Beware of methodology issues...
Tricco, A. C., Antony, J., Zarin, W., Strifler, L., Ghassemi, M., Ivory, J., . . . Straus, S. E. (2015). A scoping review of rapid review methods. BMC Medicine, 13, 224. doi:10.1186/s12916-015-0465-6
Schünemann, H. J., & Moja, L. (2015). Reviews: Rapid! Rapid! Rapid! …and systematic. Systematic Reviews, 4(1), 4. doi:10.1186/2046-4053-4-4
Evidence map – a visual summation of existing evidence
Miake-Lye, I. M., Hempel, S., Shanman, R., & Shekelle, P. G. (2016). What is an evidence map? A systematic review of published evidence maps and their definitions, methods, and products. Systematic Reviews, 5, 28. doi:10.1186/s13643-016-0204-x
Example based on an SR of SRs
Solloway, M. R., Taylor, S. L., Shekelle, P. G., Miake-Lye, I. M., Beroes, J. M., Shanman, R. M., & Hempel, S. (2016). An evidence map of the effect of Tai Chi on health outcomes. Systematic Reviews, 5(1), 126. doi:10.1186/s13643-016-0300-y
Realist review – how and why complex social interventions work
Gough, D. (2013). Meta-narrative and realist reviews: guidance, rules, publication standards and quality appraisal. BMC Medicine, 11, 22. doi:10.1186/1741-7015-11-22
Pawson, R., Greenhalgh, T., Harvey, G., & Walshe, K. (2005). Realist review - A new method of systematic review designed for complex policy interventions. Journal of Health Services Research and Policy, 10(SUPPL. 1), 21-34. doi:10.1258/1355819054308530
Note: There are many other types of review. Those above and others are identified and discussed here:
Grant, M. J., & Booth, A. (2009). A typology of reviews: an analysis of 14 review types and associated methodologies. Health Information and Libraries Journal 26(2), 91-108. doi:10.1111/j.1471-1842.2009.00848.x
Reproduced from: Bettany-Saltikov, J. (2010). Learning how to undertake a systematic review: Part 1. Nursing Standard, 24(40): 47-55.
| Systematic Review | Narrative 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 specified. 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 | |
Jahan, N., Naveed, S., Zeshan, M., & Tahir, M. A. (2016). How to conduct a systematic review: A narrative literature review. Cureus, 8(11), e864. doi:10.7759/cureus.864
Saltikov, J., & Fernandes, T. (2010). Learning how to undertake a systematic review: Part 1. Nursing Standard, 24(50), 47-55; quiz 56. Retrieved from http://ezproxy.usc.edu.au:2048/login?url=http://search.proquest.com/docview/751264535?accountid=28745
Bettany-Saltikov, J. (2010). Learning how to undertake a systematic review: Part 2. Nursing Standard, 24(51), 47-56; quiz 58, 60. Retrieved from http://ezproxy.usc.edu.au:2048/login?url=http://search.proquest.com/docview/751267350?accountid=28745
Saltman,D., Jackson,D., Newton, P.J. & Davidson, P.M. (2013). In pursuit of certainty: Can the systematic review process deliver? BMC Medical Informatics and Decision Making, 13, 25. doi:10.1186/1472-6947-13-25
http://www.biomedcentral.com/1472-6947/13/25/abstract
Petticrew, M. (2009). Systematic reviews in public health: Old chestnuts and new challenges [Editorial]. Bulletin of the World Health Organization, 87(3), 163. doi: 10.2471/BLT.09.063719 . Retrieved from http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2654648/ (Good argument for the role of SRs where there is no single clinical question).
Systematic Reviews to Support Evidence-Based Medicine. 2nd ed. by 
How to do a systematic literature review in nursing : a step-by-step guide by 
Systematic Reviews in Health Care : meta analysis in context by 
Systematic Reviews in Health Care by 
Cochrane Handbook For Systematic Reviews of Interventions
Systematic Reviews: CRD's Guidance for Undertaking Reviews in Health CareSpecial thanks to Debbie Booth and the University of Newcastle Library for permission to reuse and modify most of the information on this guide.
The original U of N guide can be viewed here.
