Statalist


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

st: RE: calculating relative risk


From   "Silcocks Paul" <Paul.Silcocks@nottingham.ac.uk>
To   <statalist@hsphsun2.harvard.edu>
Subject   st: RE: calculating relative risk
Date   Fri, 7 Dec 2007 13:01:19 -0000

With a low risk in the first place, the odds ratios will be a good
approximation to the relative risk, but if you do want to model relative
risk you'd be better off using a Poisson family with log link (or do it
more economically with a Poisson regression).  Use the robust variance
option and you should solve your problem.  See Guangyong Zou "A modified
Poisson regression approach to prospective studies with binary data" Am
J Epidemiol (2004) 159: 702-706


Paul Silcocks BM BCh, MSc, FRCPath, FFPH, CStat Clinical Senior Lecturer

Nottingham Clinical Trials Support Unit
Room B39 
School of Community Health Sciences 
University of Nottingham Medical School 
Nottingham
NG7 2UH

tel +44 115  9515151 x 30514
Direct line: +44 115 8230505. 
General office: +44 115 8230500
fax +44 115 8230515

e-mail paul.silcocks@nottingham.ac.uk
-----Original Message-----
From: owner-statalist@hsphsun2.harvard.edu
[mailto:owner-statalist@hsphsun2.harvard.edu] On Behalf Of Sue Kim
Sent: 04 December 2007 22:46
To: statalist@hsphsun2.harvard.edu
Subject: st: calculating relative risk

Hi. I have a binary outcome where the probability of outcome is low so I
want to get an adjusted relative risk (rather than odds ratio) using
glm.  When using glm with fam(bin) link(log) command, I get a warning
"parameter estimates produce inadmissible mean estimates in one or more
observation". Could I still use the results or is there a way to get
around this problem?
Thank you.
Sue




 
________________________________________________________________________
____________
Be a better friend, newshound, and
know-it-all with Yahoo! Mobile.  Try it now.
http://mobile.yahoo.com/;_ylt=Ahu06i62sR8HDtDypao8Wcj9tAcJ 

*
*   For searches and help try:
*   http://www.stata.com/support/faqs/res/findit.html
*   http://www.stata.com/support/statalist/faq
*   http://www.ats.ucla.edu/stat/stata/

This message has been checked for viruses but the contents of an attachment
may still contain software viruses, which could damage your computer system:
you are advised to perform your own checks. Email communications with the
University of Nottingham may be monitored as permitted by UK legislation.


*
*   For searches and help try:
*   http://www.stata.com/support/faqs/res/findit.html
*   http://www.stata.com/support/statalist/faq
*   http://www.ats.ucla.edu/stat/stata/



© Copyright 1996–2021 StataCorp LLC   |   Terms of use   |   Privacy   |   Contact us   |   What's new   |   Site index