Fits a cox model to an rpsftm object

This function fits a cox model to an rpsftm object. It estimates a hazard ratio for the comparison of experimental observed time compared to control latent time. In addition the variance of the treatment coefficient is inflated based on the test used in g-estimation. Any strata included in rpsftm call are used in the cox model.

rpsftm.coxph(x)

Arguments

x

rpsftm object (rpsftm)

Examples

# use data included in rpsftm package
library(rpsftm)
immdef <- rpsftm::immdef
immdef$rx <- with(immdef, 1 - xoyrs/progyrs)

# fit the model
imm.fit <- rpsftm(Surv(progyrs, prog) ~ rand(imm, rx),
                  data=immdef,
                  censor_time=censyrs)

rpsftm.coxph(imm.fit)
#> Call:
#> coxph(formula = rpsftm.formula(x), data = cfact.df)
#> 
#>         coef exp(coef) se(coef)      z      p
#> .arm -0.2633    0.7685   0.1376 -1.914 0.0556
#> 
#> Likelihood ratio test=4.72  on 1 df, p=0.02989
#> n= 1000, number of events= 285