Guides: Systematic Reviews: Introduction

What is a Systematic Review?

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:

a clearly stated set of objectives with pre-defined eligibility criteria for studies
an explicit, reproducible methodology
a systematic search that attempts to identify all studies that would meet the eligibility criteria
an assessment of the validity of the findings of the included studies, for example through the assessment of risk of bias
a systematic presentation, and synthesis, of the characteristics and findings of the included studies. (Cochrane Handbook for Systematic Reviews of Interventions, 2008, p. 6)

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.

Similiarities and Differences Between Systematic and Traditional (Narrative) Literature Reviews

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

Readings on SR methodology theory and application

Bramer, W.M., Rethlefsen, M.L., Kleijnen, J. et al. Optimal database combinations for literature searches in systematic reviews: a prospective exploratory study. Syst Rev 6, 245 (2017). https://doi.org/10.1186/s13643-017-0644-y

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).

Kable, A. K., Pich, J., & Maslin-Prothero, S. E. (2012). A structured approach to documenting a search strategy for publication: A 12 step guideline for authors. Nurse Education Today, 32(8), 878-886. doi:10.1016/j.nedt.2012.02.022

Acknowledgement

Special thanks to Debbie Booth and the University of Newcastle Library for permission to reuse and modify most of the information on this guide.

View the original U of N Systematic Review guide.