Forest plot: OS HR of MPT versus MP, by study. The HR and 95% CI are shown for each study, and the overall HR (where the dotted line bisects the diamond) and 95% CI (indicated by left and right corners of the diamond), assuming a random effects model. For each treatment arm of each study, the number of events (deaths) and number of patients (E/N) is given. There is evidence of heterogeneity (I² = 61%) that may jeopardize the P value and CI of the estimated overall effect (0.82).