How to obtain the 95% confidence interval using Uno's concordance statistics

[mili]

Hi, 

I developed a model using Cox proportional hazards regression. I would like to obtain the c-statistics using Uno's method. I would like to know how to code to obtain the 95% confidence interval. This is the code I have that provides me only with the Uno's c-statistics.

proc phreg data= cpm_10.harmo concordance= uno;
class prim_grp (ref = '1') vmet (ref = '0') / param=ref;
model survival *censored_1y(1)= prim_grp vmet lsf / ties=exact;
run;

thank you very much for your help,

Anick

[tamhane]

SAS does report standard error with it.

Uno's Concordance Statistic
Source	Estimate	Standard Error
Model	0.5464	0.1584

For 95% CI: you would multiple SE with 1.96. 

In the given example, it would be 0.1584*1.96 = 0.3105

Lower limit = 0.5464 - 0.3105 = 0.2359 

Upper limit = 0.5464 + 0.3105 = 0.8569

Thus if rounded 0.55 (0.24, 0.86) or expressed as % then 54.6 (23.6, 85.7).

Hope this helps.

Ashutosh