Efron's method of handling ties in survival data

[msuchard]

Cyclops is currently lacking support for Efron's method (default behavior in R as @schuemie brought to my attention). Default Cyclops behavior for ties in Cox regression is Breslow's method, which I believe is also the default behavior in SAS. More critically, Cyclops supports at scale an experimental exact method for handling ties that should reduce bias (manuscript in process, instructions to come); in general, exact methods are quite slow.