KM2NNT                  Calculate the NNT based on the Kaplan-Meier
                        estimated survival rates between the treatment
                        and control groups
RM2NNT                  Calculate the NNT based on the restricted mean
                        survival times between the treatment and
                        control groups
RMvsKM                  Compare the performance between the NNT-RMST
                        and NNT-KM through the average life gain per
                        patient
