Re: [R] How to understand the plotting of the cox.zph function

Any insight maybe (sorry for the bump, need this info), JT. -- View this message in context: http://r.789695.n4.nabble.com/How-to-understand-the-plotting-of-the-cox-zph-function-tp376p3814881.html Sent from the R help mailing list archive at Nabble.com. __

Re: [R] How to understand the plotting of the cox.zph function

Thank you very much for your answer. I would like to construct for presentation purposes the HR(t), not the beta(t). How can I perform this? I obtained the x-y values of the cox.zph plot time= as.numeric(as.character(rownames(cox.zph.object$y))) HR=exp(cox.zph.object$y[,1]) However when I plo

[R] How to understand the plotting of the cox.zph function

I have a coxph model which gives me HR of about 2.9 for presence of factor B (factors can be A, B, C, A as baseline in the model), with 95% CI 1.8-4.8 , p<0.001. When checking the proportionality assumption there is significant evidence that there is a violation On the link is the results of the

[R] Repeated measures cummulative logit mixed model

Dear R help gurus, I have the following problem and I would be delighted if you could help me. >From a large (1500) cohort of patients we have been taking some measurements (ECG measurements, but its not important). The measurements are ordinal in 4 grades (Grade I-IV, grade IV being the most s

[R] Trouble: Time Difference with difftime

Hello all!!! I want to measure the duration of events (given a start and an end time). The catch is that I require the output in calender days. This means: 02-Jan-2011 00:01:00 minus 01-Jan-2011 23:59:00 should be 1 day (although the real time difference is only 2 minutes) My data is the follo

Re: [R] Survival: pyears and ratetable: expected events

Hi thanks, The conventional method is solid (cross multiplication of patient years at each age and year and gender, with the corresponding risk for death at each age year and gender). I get about 26 expected deaths (verified by many different sources) Now what I am trying to do is get the same a

Re: [R] Survival: pyears and ratetable: expected events

I tried again but I cannot get a valid expected number of death directly from the pyear function. Using cross multiplication from Lifetables I am expecting in my cohort about 26 expected deaths (to match the 25 observed deaths). I have tried different variation of the pyears syntax but i get either

Re: [R] Survival: pyears and ratetable: expected events

Thanks, of course I am familiar with your work. I've read 63 but I think my answer may be in 81 (reading now). I've tried running the examples I've found in the help of the survival package, they seem to work fine, but when I parse my own variables everything gets mixed up. pyears wotks fine but wh

[R] Survival: pyears and ratetable: expected events

Dear all, I am having a (really) hard time getting pyears to work together with a ratetable to give me the number of expected events (deaths). I have the following data: dos, date of surgery, as.Date dof, date of last follow-up, as.Date dos, date of surgery, as.Date sex, gender, as.factor (femal