Statalist


[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

RE: st: Multilevel modelling of survival data


From   Maarten buis <maartenbuis@yahoo.co.uk>
To   stata list <statalist@hsphsun2.harvard.edu>
Subject   RE: st: Multilevel modelling of survival data
Date   Mon, 16 Mar 2009 21:17:43 +0000 (GMT)

--- On Mon, 16/3/09, Justin B Echouffo Tcheugui wrote:
> I tried the command stcox with the option -shared () as
> you advised. As you can see below I am not having the
> desired output:
> could not calculate numerical derivatives flat or
> discontinuous region encountered r (430)

One posibility that jumps to mind is: are there any
clinics that only have (valid) observations on either
the treatment or the controll group?

So type:

tab randomgroup clinic, if !missing(_t)

and see if any of the reported counts equal zero.

-- Maarten

-----------------------------------------
Maarten L. Buis
Institut fuer Soziologie
Universitaet Tuebingen
Wilhelmstrasse 36
72074 Tuebingen
Germany

http://home.fsw.vu.nl/m.buis/
-----------------------------------------


      

*
*   For searches and help try:
*   http://www.stata.com/help.cgi?search
*   http://www.stata.com/support/statalist/faq
*   http://www.ats.ucla.edu/stat/stata/



© Copyright 1996–2014 StataCorp LP   |   Terms of use   |   Privacy   |   Contact us   |   What's new   |   Site index