[Date Prev][Date Next][Thread Prev][Thread Next][Date index][Thread index]

st: RE: query about cox model with shared frailty

From   "Nick Cox" <[email protected]>
To   <[email protected]>
Subject   st: RE: query about cox model with shared frailty
Date   Tue, 2 Sep 2008 17:05:33 +0100

Please note that the correct term is Cox model to acknowledge that a
person, Sir David Cox, lies behind it! 

[email protected] 
(correlated, but not related) 

Murali Kuchibhotla

      I a trying to fit a cox regression model for a dataset consisting
of 2
groups-trainees and non-trainees. Because I suspect within-group
correlation in
failure times, the standard cox model is likely to be misspecified,
which I
would like to correct for by using the -shared()- option,as in below:

stcox ability_score male edu_yrs,shared(treatment_new)

Now my question is the following: since the shared frailty model is
supposed to
account for within-group correlation, shouldn't it report different
frailty variances for each group(trainees and non-trainees)as well as a
corresponding set of parameter estimates for each group, as opposed to
what it
actually reports- a single set of parameter estimates and one estimated

*   For searches and help try:

© Copyright 1996–2024 StataCorp LLC   |   Terms of use   |   Privacy   |   Contact us   |   What's new   |   Site index