Exercise 28. Flexible parametric survival models in R
library(biostat3)
library(rstpm2) # for the flexible parametric model
library(dplyr) # for data manipulation
data(melanoma)
## Extract subset and create 0/1 outcome variables
melanoma0 <- melanoma %>% filter(stage=="Localised") %>%
mutate(event = ifelse(status=="Dead: cancer" & surv_mm<120, 1, 0),
time = pmin(120, surv_mm)/12,
agegrp1 = (agegrp=="0-44")+0, # used by time-dependent effect
agegrp2 = (agegrp=="45-59")+0, # used by time-dependent effect
agegrp3 = (agegrp=="60-74")+0, # used by time-dependent effect
agegrp4 = (agegrp=="75+")+0) # used by time-dependent effect