Systematic Reviews

A systematic review is a comprehensive literature search and synthesis project that tries to answer a well-defined question using existing primary research as evidence. A protocol is used to plan the systematic review methods prior to the project, including what is and is not included in the search.

Systematic reviews are often used as the foundation for a meta analysis (a statistical process that combines the findings from individual studies) and to re-evaluate clinical guidelines.

Systematic review and meta analysis are both types of evidence synthesis methods. Read more about evidence synthesis on the Types of Reviews page of this guide.

Advanced Literature Searching in the Health Sciences MOOC (Massive Open Online Course)

• Covers Fundamental components of advanced literature searching for projects such as systematic reviews, scoping reviews, and clinical practice guidelines
• 9 weeks of content with approximately 2-4 hours of effort per week
• Free with verified certificate available for a fee
• Designed by ​Informationists at the University of Michigan Taubman Health Sciences Library

Introduction to Systematic Review and Meta-Analysis MOOC

• Introduces methods and processes for systematic reviews and meta-analyses
• 6 weeks of content with approximately 1-3 hours of effort per week
• Free with certificate available for a fee
• Offered by Johns Hopkins University

The figure¹ below gives a high-level overview of the stages of the meta-analysis process. Related evidence synthesis methods may omit steps in the meta-analysis process; for example, systematic reviews will not include Step 14 meta-analyze.

Note the iterative nature of the process as search updates are conducted later in the project at Step 13 (an arrow on the left connects to Step 6 de-duplicate).

While this figure highlights appraisal of relevance in Steps 7 (screen abstracts) and 9 (screen full text), guidelines recommend critical appraisal of the individual study's validity and results once it is selected for inclusion.

¹Tsafnet, G., Glasziou, P., Choong, M.K., et al. Systematic review automation technologies. Systematic Reviews 2014; 3:74;  http://www.systematicreviewsjournal.com/content/3/1/74.