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 the file leukemia.dta I used (Stata)
Here are the codes for R
leukemia=read.fwf(file="leukem.txt",widths=c(4,2,3,2,5,2),col.names=c("id","TREAT","TIME","STATUS","LOGWBC",
"GENDER"))
library(survival)
res <- coxph(Surv(TIME, STATUS)~TREAT, data=leukemia)
summary(res)
and here the codes for for stata
infix ID 2-3 TREAT 6 TIME 8-9 STATUS 11 LOGWBC 12-16 GENDER 18 using
"g:rleukem.txt",clear
stset TIME, failure(STATUS==1)
stcox TREAT
SPSS and EPIinfo give the same HR than Stata
I tried with an other database without any problem
What would be the problem??? I changed of pc and versions of R (2.81 & 2.9.0)
without any change. The means are the same for the two packages.
I saw a few posts with discrepancies but not with the same database
Thanks in advance
Michel Boutsen
Brussel's University
Department of Biostatistics 1 1 6 1 2.31 0
2 1 6 1 4.06 1
3 1 6 1 3.28 0
4 1 6 0 3.2 0
5 1 7 1 4.43 0
6 1 9 0 2.8 0
7 1 10 1 2.96 0
8 1 10 0 2.7 0
9 1 11 0 2.6 0
10 1 13 1 2.88 0
11 1 16 1 3.6 1
12 1 17 0 2.16 0
13 1 19 0 2.05 0
14 1 20 0 2.01 1
15 1 22 1 2.32 1
16 1 23 1 2.57 1
17 1 25 0 1.78 1
18 1 32 0 2.2 1
19 1 32 0 2.53 1
20 1 34 0 1.47 1
21 1 35 0 1.45 1
22 2 1 1 2.8 1
23 2 1 1 5 1
24 2 2 1 4.91 1
25 2 2 1 4.48 1
26 2 3 1 4.01 1
27 2 4 1 4.36 1
28 2 4 1 2.42 1
29 2 5 1 3.49 1
30 2 5 1 3.97 0
31 2 8 1 3.52 0
32 2 8 1 3.05 0
33 2 8 1 2.32 0
34 2 8 1 3.26 1
35 2 11 1 3.49 0
36 2 11 1 2.12 0
37 2 12 1 1.5 0
38 2 12 1 3.06 0
39 2 15 1 2.3 0
40 2 17 1 2.95 0
41 2 22 1 2.73 0
42 2 23 1 1.97 1
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