Hi. I am using Windows version of R 1.8.1. Being somewhat new to survival analysis, I am trying to compare cph (Design) with coxph (survival) for use with a survival data set.
I was wondering why cph and coxph provide me with different confidence intervals for the hazard ratios for one of the variables. I was wondering if I am doing something wrong? Or if the two functions are calculating hazard ratios and the 95% confidence intervals differently? I have listed part of the code and part of the results from the 2 functions. Sorry if this question is a repeat, I didn't find it when I searched the archives. ########################################################### # s= Surv(Time1, Time2, censor) #f= coxph(s~ Siblings + Weight.at.age.4) #summary(f) #Call: #coxph(formula = s ~ Siblings + Weight.at.age.4) # n= 132 # exp(coef) exp(-coef) lower .95 upper .95 #Siblings 1.52 0.657 0.815 2.84 #Weight.at.age.4 0.91 1.099 0.772 1.07 ############################################################## #s= Surv(Time1, Time2, censor) #f= cph(s~ Siblings + Weight.at.age.4,surv=TRUE , x=T, y = T) # summary(f) # Effects Response : s # Factor Low High Diff. Effect S.E. Lower 0.95 Upper 0.95 # Siblings 0.000 1.000 1.0000 0.42 0.32 -0.20 1.04 # Hazard Ratio 0.000 1.000 1.0000 1.52 NA 0.82 2.84 # Weight.at.age.4 8.613 10.602 1.9885 -0.19 0.17 -0.51 0.14 # Hazard Ratio 8.613 10.602 1.9885 0.83 NA 0.60 1.15 Sincerely Deb Montgomery Department of Fisheries and Wildlife Resources University of Idaho Moscow, Idaho 83843 208-885-4008 [EMAIL PROTECTED] ______________________________________________ [EMAIL PROTECTED] mailing list https://www.stat.math.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
