What do small squares in a meta-analysis exhibit?

Small squares in a meta-analysis typically represent the mean effect size estimated from the studies included in that analysis. In a forest plot, which is commonly used to illustrate meta-analyses, each study is typically represented by a square. The size of each square often reflects the weight or sample size of the study, indicating its contribution to the overall effect size estimation. The mean effect size is an important summary statistic in meta-analysis, as it gives a single value that reflects the overall impact or association assessed across multiple studies.

This representation of the mean effect size is crucial for synthesizing evidence, as it allows researchers and clinicians to see a consolidated measure of the effect being analyzed, facilitating decision-making processes based on the available evidence.