Sample forest plot (data are fictitious). This forest plot presents data from 5 fictional studies, two of which were “statistically significant” (studies 2 and 5) as indicated by confidence intervals that did not cross 1. Study 5 accounts for about 42% of the patients included in the systematic analysis. In sum, the meta-analysis suggests that the odds ratio in the combined analysis is 0.67 and is statistically significant, with odds ratios from 0.55 to 0.82. The advantage of systematic reviews over narrative reviews can also be inferred from this figure: a narrative review may have chosen to examine studies 1,3 and 4 and concluded that there was no difference in favour of treatment. Note that although this figure summarizes the results of the statistically pooled data, it does not explore the quality of the contributing studies (this information is usually presented in the text or an accompanying table).