competing risk model with time dependent covariates

[phguardiol@aol.com]

Dear S users,

is there a way, I mean a package, to perform a competing risk model which can handle time dependent covariates ?

my main covariate (additional treatment to patients) appears not to follow the proportional hazards assumption, its effect being observed after one year of treatment but not before (this is expected / makes sense on a clinical point of view). SO I was planning to use a time dependent Cox model with 2 time intervals for patients < > 1 year etc...

However, a large number of patients dies from treatment related complications of unrelated to the disease and the treatment (elderly patients) so to analyze the effect of my covariate of interest on disease free survival and relapse incidence, I d like to use a competing risk model such as the Gray CMPRSK.

My problem is that I cannot have multiple "lines" for the same patient with this package (for time dep covariates 2 or 3 lines with same Id /UPN).
How can I manage this !!!???
Any help will be greatly appreciated
Thanks
Yours sincerely

Philippe Guardiola