[R] discrepancies between stata and r for a cox regression

2009-05-18 Thread Michel Boutsen
Hello I would like to develop the use of R. Trying R and more particulary the cox model, I am surprised by discrepancies between results with stata and R for a cox model With the same data base, I get a hazard ratio (4.82) that is not the same obtained with stata (4.52) You will find attached

Re: [R] discrepancies between stata and r for a cox regression

2009-05-18 Thread Gary Collins
try res <- coxph(Surv(TIME, STATUS)~TREAT, data=leukemia, method="breslow") R default for handling ties is Efron's method, whereas it's Breslow for STATA. Have a look under method in ?coxph it clearly states this, and STATA output clearly states the Breslow method for ties in the output of

Re: [R] discrepancies between stata and r for a cox regression

2009-05-18 Thread Achim Zeileis
On Mon, 18 May 2009, Michel Boutsen wrote: Hello I would like to develop the use of R. Trying R and more particulary the cox model, I am surprised by discrepancies between results with stata and R for a cox model With the same data base, I get a hazard ratio (4.82) that is not the same obta

[R] discrepancies between stata and r for a cox regression

2009-05-18 Thread Michel Boutsen
Hello I would like to develop the use of R. Trying R and more particulary the cox model, I am surprised by discrepancies between results with stata and R for a cox model With the same data base, I get a hazard ratio (4.82) that is not the same obtained with stata (4.52) You will find attached