What Is a Forest Plot?

Looking for the full method? Read the detailed guide: How to Interpret a Forest Plot.

A forest plot is a graph used in meta-analysis that shows the effect estimate and confidence interval for each included study, usually with a pooled estimate at the bottom. It lets you see size, direction and consistency of effects at a glance.

Example

Invented for teaching: Each study appears as a square on a horizontal line; the line shows its 95% confidence interval. A vertical line marks no effect (1 for ratios, 0 for differences), and a diamond shows the pooled result.

Common misunderstanding

A pooled diamond is not necessarily the "truth": it inherits the biases of the studies and may hide heterogeneity. Also, a confidence interval that crosses the line of no effect means the result is uncertain, not that there is definitely no effect.

Learn more

See How to Interpret a Forest Plot. MRN's free forest plot generator can draw one from your own numbers.

This page is general educational information about research methods. It is not medical, legal or regulatory advice; follow your institution's ethics board and your target journal's instructions.