rstpm2: cox.tvc – R documentation

Become an expert in R — Interactive courses, Cheat Sheets, certificates and more!

cox.tvc

Test for a time-varying effect in the coxph model

Description

Test for a time-varying effect in the coxph model by re-fitting the partial likelihood including a time-varying effect, plot the effect size, and return the re-fitted model. The main advantage of this function over the tt() special is that it scales well for moderate sized datasets (cf. tt which expands the dataset and scales very poorly).

Usage

cox.tvc(obj, var=NULL, method="logt")

Arguments

`obj`	A `coxph` object. Currently restricted to right censoring with Breslow ties and without stratification, etc.
`var`	String for the effect name. Currently assumes simple continuous effects.
`method`	A string representing the possible time transformations. Currently only "logt".

Value

Returns a tvcCoxph object (which inherits from the mle2 class) of the re-fitted model.

Examples

## As per the example for cox.zph:
fit <- coxph(Surv(futime, fustat) ~ age + ecog.ps,  
             data=ovarian) 
temp <- rstpm2:::cox.tvc(fit, "age") 
print(temp)                  # display the results 
plot(temp)                   # plot curves

rstpm2

Smooth Survival Models, Including Generalized Survival Models

v1.5.2

GPL-2 | GPL-3

Authors

Mark Clements [aut, cre], Xing-Rong Liu [aut], Benjamin Christoffersen [aut], Paul Lambert [ctb], Lasse Hjort Jakobsen [ctb], Alessandro Gasparini [ctb], Gordon Smyth [cph], Patrick Alken [cph], Simon Wood [cph], Rhys Ulerich [cph]

Initial release

2021-02-21