A blinded SSR does not require knowledge of the treatment assignment at the individual
patient level. It is designed to modify sample size due to inaccurate assumptions
of the variability associated with a continuous endpoint or an assumed background
event rate in the control arm for trials with a binary endpoint. Even though the treatment
assignment information is very helpful in assessing such parameters, methods have
been developed to allow their estimation without using the actual treatment assignment
information.
Because blinded SSR does not involve treatment unblinding and can be conducted without worrying about introducing bias into a trial, blinded SSR is classified as a “well-understood” adaptive feature in the ...