Displaying 2 results from an estimated 2 matches for "iptw".
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ipfw
2011 Sep 12
1
coxreg vs coxph: time-dependent treatment
...the point). Will appreciate any explaination /
comment.
cheers,
Ehsan
############################
require(survival)
require(eha)
data(heart)
# create weights
follow <- heart$stop - heart$start
fit <- glm(transplant ~ age + surgery + year + follow,
data=heart, family = binomial)
heart$iptw <- ifelse(heart$transplant == 0,
1 - predict(fit, type = "response"),
predict(fit, type = "response"))
summary(heart$iptw)
# no weights (basic calculation)
fit0 <- coxph(Surv(start,stop,event)~transplant, data=heart)
fit0 # fit with coxph without case-weights
fit1 <...
2012 Feb 21
2
bootstrap in time dependent Cox model
...censboot' be appropriate to use in
this context? Any suggestions/references/direction to R-package will
be highly appreciated.
Thanks
Ehsan
###########################
> dataset = read.csv("http://stat.ubc.ca/~e.karim/dataset2.csv")
> head(dataset) # (tx = treatment, weight = IPTW)
id tx enter exit event weight
1 1 0 0 1 0 1.037136
2 1 0 1 2 0 1.299079
3 1 0 2 3 0 1.352642
4 1 1 3 4 0 1.245575
5 1 0 4 5 0 1.360458
6 1 0 5 6 0 1.236780
> time.dep.weighted.cox = coxph(Surv(enter, exit, event)...