[R] Hazard ratio
R Help
rhelp.stats at gmail.com
Thu Dec 10 15:45:49 CET 2009
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 <sewashm at gmail.com> wrote:
> 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 0.6665
> factor(y1)3 -0.510124 0.600421 0.088901 -5.738 9.57e-09 ***
> factor(x2)2 -0.510124 0.600421 0.088901 -5.738 9.57e-09 ***
>
>
>
> What are those values? Is it comparing in reference to the first
> class of each covariate?
>
> Thanks again.
>
>
>
>
>
>
> On Thu, Dec 10, 2009 at 8:33 AM, Ashta <sewashm at gmail.com> 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 ? .
>>
>>
>> The other question is that how do I interpret the second column in
>> the second panel (i.e., exp(-coef))
>>
>> I used the model
>> coxfit1 <- coxph(Surv(sdat$time, sdat$cens)~ y1+x2)
>>
>> coef exp(coef) se(coef) z Pr(>|z|)
>> y1 -0.024084 0.976204 0.003077 -7.828 5.00e-15 ***
>> x2 0.036161 1.036822 0.083921 0.431 0.6665
>>
>> exp(coef) exp(-coef) lower .95 upper .95
>> y1 0.9762 1.0244 0.9703 0.9821
>> x2 1.0368 0.9645 0.8796 1.2222
>>
>>
>> Thanks in advance
>>
>
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>
More information about the R-help
mailing list