gen_surv_times function

Generate survival times

Generate survival times according to hazard rate $h(t) \exp(\mu)$ with $h(t)$ the hazard rate associated with the specified inverse cumulative hazard rate invchaz and $\mu$ the specified true hazard ratio mu. See Bender et al. (2005).

gen_surv_times(invchaz, mu = log(1), data, coxphmod = NULL)

Arguments

• invchaz: the inverse cumulative (baseline) hazard rate to be used for generating survival times. Must take vector inputs!

• mu: the true hazard ratio used to generate survival times.

• data: an integer number of survival times to generate or (in combination with coxphmod): a data.frame containing subject covariates in named columns.

• coxphmod: (optional) a cox proportional hazards regression model as produced by the function coxph(). Standard practice:

  coxph(Surv(survtime, censorid) ~ covariates, data = data).

  Alternatively, a list with:

  • $formula (~ covariates)
  • $coefficients (named vector specifying risk adjustment coefficients for covariates - names must be the same as in$formula and colnames of data).

Returns

A vector of survival times from subject entry time.

Details

Sometimes it is desirable to generate survival times from an increased hazard rate

with $h_0$ the baseline hazard rate. We call $exp(\mu)$ the true hazard ratio.

Examples

set.seed(123)
gen_surv_times(invchaz = function(t) inv_chaz_exp(t, lambda = 0.01), data = 5)

References

Bender, R., Augustin, T., & Blettner, M. (2005). Generating survival times to simulate Cox proportional hazards models. Statistics in Medicine, 24(11), 1713-1723. tools:::Rd_expr_doi("10.1002/sim.2059")

Author(s)

Daniel Gomon