We would like to report an erratum to the paper titled ‘Time-to-event analysis with treatment arm selection at interim’ by Di Scala and Glimm, Statistics in Medicine. On page 3070 of our paper, the definition of ϕk following formula (4) should be ϕk = pk1pk2. Formula (4) thus becomes
Because of the definition of pkj on page 3069, pk1pk2 = 0 if k ≠ C. This renders the factor in the definition of ϕk unnecessary. An alternative way to write formula (4) is
Computations in our paper are correct, and all subsequent derivations and simulations are not affected by the correction to this formula.
We are grateful to the readers who kindly brought this typographical error to our attention.