Evidence guide

What Is a Systematic Review?

A systematic review uses a documented search and selection process to answer a focused question from all eligible evidence.

More than a literature summary

Good reviews predefine eligibility, search multiple databases, assess bias and explain how evidence was synthesized.

Review quality varies

A narrow search, vague criteria or failure to assess study quality can produce a polished but unreliable overview.

Systematic review versus meta-analysis

A review can be systematic without pooling numbers. A meta-analysis is the statistical component when studies are sufficiently comparable.

A practical reading checklist

  1. Was a protocol registered?
  2. Are full search terms reported?
  3. Did two reviewers select studies independently?
  4. Was certainty of evidence graded?