Subject Guides

Systematic Review

A step by step guide

What is a Systematic Review?

"A systematic review attempts to identify, appraise and synthesize all the empirical evidence that meets pre-specified eligibility criteria to answer a specific research question. Researchers conducting systematic reviews use explicit, systematic methods that are selected with a view aimed at minimizing bias, to produce more reliable findings to inform decision making."

Source: https://www.cochranelibrary.com/about/about-cochrane-reviews

Required elements of a Systematic Review:

  • A team to ensure unbiased screening
  • Conducted according to Cochrane OR JBI guidelines
  • Reported according to the PRISMA standards
  • File a protocol a priori
  • Reproducible and transparent search strategies of multiple applicable databases and  grey literature resources: PRISMA-S
  • Two phases of screening: Title/Abstract and Full Text by at least 2 screeners
  • Documentation of included and excluded studies according to the PRISMA flow diagram
  • Critical Appraisal of all included studies
  • Documentation of data extraction process per protocol
  • Citation of included studies, guidelines and tools utilized

The purpose of a systematic review is provide a synthesized, comprehensive view of the available literature on a specific topic. The systematic review methodology must be transparent, reproducible with strong validity and low risk of bias.  

Systematic Review Process Map

7 simplified steps to a systematic review

Systematic Review Timeline

With 5 team members, an average systematic review takes approximately 62 - 67 weeks (Borah, et. al. , 2016)

Getting started Assemble team and member roles, develop & refine research question, determine inclusion & exclusion criteria, acquire exemplar articles, meet with a librarian to develop search strategy, begin the protocol application 4-6 weeks
Primary search design Determine applicable databases, grey literature sources and develop pilot search strategy. Complete pilot screening process. Confirm changes for final search strategy 6-8 weeks
Finalize search design Adapt search strategy according to pilot screening feedback, peer review of finalized search strategy, run final search and begin title/abstract screening. 6-8 weeks
Screening Phase 1: Title and abstract screening. Phase 2: Full text screening    8-12 weeks
Critical appraisal  Appraise quantity of included studies 8-12 weeks
Data extraction  Based upon a priori protocol 8-12 weeks
Write the review Refer to reporting standards and guidelines: PRISMA 2020 8-12 weeks

This table is an estimate of time to complete based on a team of 4-6 FTE researchers working with an experienced librarian. 

Systematic Review Guidance

  • Aromataris E, Munn Z (Eds.). (2020). JBI Manual for Evidence Synthesis. Available from https://synthesismanual.jbi.global and https://doi.org/10.46658/JBIMES-20-01
  • Campbell, M., McKenzie, J. E., Sowden, A., Katikireddi, S. V., Brennan, S. E., Ellis, S., … & Thomson, H. (2020). Synthesis without meta-analysis (SWiM) in systematic reviews: reporting guideline. BMJ, 368.https://doi.org/10.1136/bmj.l6890
  • Higgins J.P.T., Thomas J., Chandler J., Cumpston M., Li T., Page M.J., Welch V.A. (Eds.). (2020 update). Cochrane Handbook for Systematic Reviews of Interventions version 6.1 (updated September 2020). Cochrane. https://training.cochrane.org/handbook/current 
  • Institute of Medicine (US) Committee on Standards for Systematic Reviews of Comparative Effectiveness Research, Eden, J., Levit, L., Berg, A., & Morton, S. (Eds.). (2011). Finding what works in health care: Standards for systematic reviews. National Academies Press (US). https://pubmed.ncbi.nlm.nih.gov/24983062/
  • Page, M. J., McKenzie, J. E., Bossuyt, P. M., Boutron, I., Hoffmann, T. C., Mulrow, C. D., … & Moher, D. (2021). The PRISMA 2020 statement: an updated guideline for reporting systematic reviews. BMJ. https://doi.org/10.1136/bmj.n71