Forest plot
A Forest plot , even forest chart , forest graphics or Blobbogramm is a graph showing the results of a meta-analysis of several studies. As a rule, the numerical result of each individual study is represented as a box on a horizontal axis, for example in medical studies the improvement rate achieved through a treatment as a percentage. The size of the box can indicate the discriminatory power (statistical power) of the study. The spread of the measured values ( variance , confidence interval ) can be indicated with a horizontal line through the box. So it is a modified box plot .
Forest plots have been common since the 1970s. They allow the reader of the meta-analysis a quick visual orientation about common trends of the analyzed studies.
The name Forest-Plot ("forest drawing") should aim at the multitude of parallel lines, reminiscent of a group of trees.