[R] Hazard ratio calculation and KM plot p-value:

I have two questions: 1) Can anyone provide me with a reference regarding calculation of Hazard ratio for two groups of data. How is it being manually calculated with an example. Unlike median time ratio which is the ratio of median times in two groups, at what time is the hazard ratio

[R] hazard ratio between my groups

HI, I am interested in calculating hazard ratio of the stratified groups defined by me. library(survcomp) binscores - cut(scores.train,c(-1000,-1,1,1000),c(low,intermediate,high)) dd - data.frame(surv.time=OS, surv.event= status, strat=binscores) km.coxph.plot(formula.s=Surv(surv.time,

[R] Hazard ratio

Hi all, I want to calculate hazard ratio within each covariate Example, one covariate has 3 classes (1,2 and 3) and x2 has 2 classes I want to compare the relative risk ratio within each class of the covariate. How do I get this result ? . The other question is that how do I interpret

Re: [R] Hazard ratio

On Dec 10, 2009, at 8:33 AM, Ashta wrote: Hi all, I want to calculate hazard ratio within each covariate Example, one covariate has 3 classes (1,2 and 3) and x2 has 2 classes I want to compare the relative risk ratio within each class of the covariate. How do I get this result ? .

Re: [R] Hazard ratio

David, Thank you very much for your response. I fitted the model as factor instead of numeric. coxfit1 - coxph(Surv(sdat$time, sdat$cens)~factor(y1)+factor(x2) coef exp(coef) se(coef) z Pr(|z|) factor(y1)2 0.036161 1.036822 0.083921 0.431

Re: [R] Hazard ratio

Yes, in this case it's comparing to the value '1'. In general with factors it's comparing to whatever level is missing. Sam On Thu, Dec 10, 2009 at 10:40 AM, Ashta sewa...@gmail.com wrote: David, Thank you very much for your response. I fitted the model as  factor instead of numeric.

[R] hazard ratio of interaction Cox model

Dear Forum, I have a question about interaction estimate in the Cox model: why the hazard ratio of the interaction is not produced in the summary of the model? (Instead, the estimate of the coefficient is given in the print of the model.) # Example: modINT -cph( Surv(T_BASE, T_FIN,STATUS)~