coxphERR {clinfun} | R Documentation |
Calculates the contribution of a subset of covariates to the explained relative risk derived from the full Cox proportional hazards model.
coxphERR(phfit, ngamma=NULL)
phfit |
The output from a proportional hazards fit. |
ngamma |
A vector of indices corresponding to covariates of interest. If missing (default), the explained relative risk is computed for the full model. |
The object phfit should be the result of a call to coxph with the option x=TRUE.
The function coxphERR returns the vector (ERR, se.ERR). The first component ERR represents the contribution of a subset of covariates to the explained relative risk estimate of the full model. If a set of covariates is not provided, then it computes the estimate of the full model. The second component se.ERR is the standard error of the estimate.
Heller G. (2012) A measure of explained risk in the proportional hazards model. Biostatistics
## Not run: library(survival) ovarianfit <- coxph(Surv(futime, fustat) ~ age + resid.ds + rx + ecog.ps, data=ovarian,x=T) # Compute the explained relative risk (ERR) and # its standard error (se.ERR) for the full model. coxphERR(ovarianfit) # Compute the contribution of age and ECOG performance status to # the explained relative risk. Age and ECOG performance status are # the first and fourth covariates in the model. coxphERR(ovarianfit, c(1,4)) ## End(Not run)