probafix: Probabitility of event when the follow-up is fixed

In coprimary: Sample Size Calculation for Two Primary Time-to-Event Endpoints in Clinical Trials

Description

In a fixed follow-up design, each subject can only be followed during a fixed period (Tf < infinite) and then goes off study. Using similar reasoning to K. Kim and A.A. Tsiatis (1990), it is easy to compute the probability.

Usage

probafix(surv,time,duraccrual,durfollow,limit,gamma)

Arguments

surv	Survival estimates
time	Time estimate
duraccrual	Accrual duration, expressed in t time units
durfollow	Follow-up duration
limit	Time limit to estimate the survival probability
gamma	the probability of observing an event by time t

Details

The probafix function estimates the probability of event when the follow-up is fixed.

Value

probafix: event probability at time limit

References

K. Kim, A.A. Tsiatis, Study duration for clinical trials with survival response and early stopping rule, Biometrics 46 (1990) 81-92

coprimary documentation built on May 1, 2019, 10:10 p.m.