Methods
STAGGERED
We estimate all summary measures after fitting a flexible parametric survival model under proportional hazards, with two internal spline knots placed at the 33% and 67% quantiles of the uncensored survival times. We fit this flexible parametric model on the time-since-randomisation scale, either using all available information or censoring after 3 years. These two options correspond to the ‘staggered’ and ‘non-staggered’ scenarios in Freidlin et al.