L'Abbe ´ plot is often used in the meta-analysis of the clinical trials where the result is the binary response of it. The event risk (number of events/number of the patients in a group) in the treatment groups are plotted against risk for the controls of each trial. If the trials are quite homogeneous the points will form the 'cloud' near to a line, the gradient of which will correspond to the joint treatment effect. Large deviations or scatter would signify possible heterogeneity.