Message-ID: <20050826171620.71647.qmail@web34011.mail.mud.yahoo.com>
Date: 2005-08-26T17:16:20Z
From: Osman Al-Radi
Subject: compare c-index of two logistic models using rcorrp.senc() of the Hmisc library
Dear R-help,
Would it be appropriate to do the following to
calculate a p-value for the difference between c-ind
of x1 and c-inx of x2 using the output from
rcorrp.senc()
> r<-rcorrp.senc(x1,x1,y)
> pValue<-1-pnorm((r[11]-r[12])/(r[2]/r[5])*1.96)
Osman O. Al-Radi, MD, MSc, FRCSC
Chief Resident, Cardiac Surgery
University of Toronto, Canada