Conclusion
Both the choice of summary measure and analysis method are very important for clinical trials designed with time-to-event outcomes, particularly for non-inferiority trials. Simply relying on the HR estimated with a Cox model as a default should be discouraged. Clinical considerations should come first to choose a meaningful summary measure. If clinical considerations are equal and the hazards are likely to be proportional, then DRMST estimated under proportional hazards seems preferable, since it nearly always has power better or the same as HR or DS.