Meta-Analysis To Assess Efficacy in Colorectal Cancer

In this meta-analysis, tumor responses and survival were analyzed combining the data from the different trials using patient individual data. The statistical methodology was based on the classical notion of stratification, consisting of estimating a treatment effect within each trial, and then overall. A statistic for heterogeneity between the trials was calculated. A test of overall treatment effect was calculated. The following quantities were used in the calculation: O, which is the number of untoward events observed in the treatment group, E, which is the number of events that would be expected in the treatment group if there were no differences between treatment and control; and V, the variance of the number of events. Those data were shown graphically in a forest plot.