DS
EVENTS, DISEASE
A common critique of DRMST is that it places too much weight on early differences in survival. In certain disease areas, only the final survival probability matters. An alternative summary measure is the difference in the survival proportions at a specified time 
DS is an absolute summary measure, relevant in the presence or absence of proportional hazards.DS is a good summary measure when interest lies only in survival by a certain time point, so that whether events happened earlier or later does not matter as long as they happened before that time point. As with DRMST, this implies that we are not interested in what happens after time 