calogrank function

Survival curves analysis of covariance

Logrank test to compare survival curves adjusting for covariates

calogrank(ftime, fstatus, grp, cvt, strat=NULL)

Arguments

• ftime: failure times
• fstatus: status indicator
• grp: group indicator
• cvt: continuous covariates used for adjusted analysis
• strat: stratification variable

Details

calogrank is the covariate adjusted version of k-sample survdiff. The function in its current form only does basic error checking.

Examples

## Not run:
  library(survival)
  data(pbc)
  pbc1 <- pbc
  pbc1$trt[pbc1$trt == -9] <- NA
  pbc1$copper[pbc1$copper == -9] <- NA
  # only death (2) is considered; transplant(1) is censored
  calogrank(pbc1$time, pbc1$status==2, pbc1$trt, pbc1[,c("copper")])
  calogrank(pbc1$time, pbc1$status==2, pbc1$trt,
                                  pbc1[,c("protime", "copper")])
## End(Not run)

References

Heller G. and Venkatraman E.S. (2004) A nonparametric test to compare survival distributions with covariate adjustment. JRSS-B 66, 719-733.