Determining whether the mITT estimator is appropriate
’
EVENT
Two key factors can be used to determine whether the ‘always initiators’ principal stratum can be identified, thus ensuring the mITT estimator in Second, we must be able to assume that the occurrence of the intercurrent event is not affected by treatment allocation (i.e. that if the intercurrent event occurs for a participant under one treatment condition, it would also occur under the other treatment condition). Together, these two factors justify the assumption of no ‘intervention initiators’ and no ‘control initiators’.