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Systematic Reviews

This guide explains the principles of systematic reviews and offers advice on getting started with your systematic literature search.

Research Informationist

Bethany Myers's picture
Bethany Myers
12-077 Center for Health Sciences

Systematic Reviews and the UCLA Library

The UCLA Biomedical Library librarians are available to consult on systematic review projects.

What Is a Systematic Review?

According to the Cochrane Handbook, section 1.2.2, "the 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; and
  • a systematic presentation, and synthesis, of the characteristics and findings of the included studies."

Green S, Higgins JPT, Alderson P, Clarke M, Mulrow CD, Oxman AD. Chapter 1: Introduction. In: Higgins JPT, Green S (editors), Cochrane Handbook for Systematic Reviews of Interventions Version 5.1.0 (updated March 2011). The Cochrane Collaboration, 2011. Available from

A systematic review is fundamentally different from a traditional narrative review. For more information, see Types of Literature Reviews.

Is Your Review Systematic?

Are you sure your review is systematic? A systematic review requires…

Why Do a Systematic Review?

The goal of a systematic review is to reduce bias and produce high quality evidence.

For more information about the types of reporting bias that necessitate an exhaustive literature search, see the Cochrane Bias Methods Group.

Rigorous systematic reviews are at the top of representations of research evidence (see below). The synthesis of multiple high-quality studies creates a single product out of all the best known evidence.

Further Reading