R help - Jun 2006 - compare odds ratios

Hi there, is there any way to compare 2 odds ratios? I
have two tests that are supposed to detect a disease
presence. So for each test, I can compute an odds
ratio. My problem is how can I compare the 2 tests by
testing whether the 2 odds ratios are the same?

Appreciate

Hi dear all, I haven't heard any suggestions on how to
tackle the problem in my previous email yet. I
searched on google and was not getting any useful
information yet. I did get someone from google groups
suggesting Cockran Mantel Haenszel test with each
subject as the stratum. But as far as I understand,
CMH test is to test whether the common odds ratio
(assuming odds ratios across stratum are equal) is
equal to 1, not really the question I was asking which
was whether the 2 odds ratios were equal (doesn't
matter if they are equal to 1). Also, someone
suggested loglinear regression, but I am not sure
either how to set things up for my problem.

One clarification to my original email: the 2
diagnostic tests were performed on the set set of
patients, the issue here how to test whether the 2
odds ratios for the 2 diagnostic tests are equal.

Here is a hypothetical dataset, for example:

dat<-cbind(disease=sample(c(rep(1,15),rep(0,20))),test1=sample(c(rep(1,11),rep(0,24))),test2=sample(c(rep(1,14),rep(0,21))))

Hope some statistical experts would guide me some
directions. Many thanks


--- array chip <arrayprofile at yahoo.com> wrote:
> Hi there, is there any way to compare 2 odds ratios?
> I
> have two tests that are supposed to detect a disease
> presence. So for each test, I can compute an odds
> ratio. My problem is how can I compare the 2 tests
> by
> testing whether the 2 odds ratios are the same?
> 
> Appreciate
> 
> ______________________________________________
> R-help at stat.math.ethz.ch mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide!
> http://www.R-project.org/posting-guide.html
>

You could try a test for heterogeneity of the odds ratios, usually part
of a Mantel-Haenszel analysis, with each test as a stratum.  Also, the
field of meta-analysis has tests for heterogeneity of estimates.  Both
are covered in Rothman and Greenland's Modern Epidemiology (1998) text,
Chapters 15 and 32 respectively.  

Daniel Smith
Environmental Health Investigations Branch
California Department of Health Services

> -----Original Message-----
> 
> Message: 43
> Date: Tue, 27 Jun 2006 11:22:14 -0700 (PDT)
> From: array chip <arrayprofile at yahoo.com>
> Subject: Re: [R] compare odds ratios
> To: r-help at stat.math.ethz.ch
> Message-ID: <20060627182214.88643.qmail at
web35709.mail.mud.yahoo.com>
> Content-Type: text/plain; charset=iso-8859-1
> 
> Hi dear all, I haven't heard any suggestions on how to
> tackle the problem in my previous email yet. I
> searched on google and was not getting any useful
> information yet. I did get someone from google groups
> suggesting Cockran Mantel Haenszel test with each
> subject as the stratum. But as far as I understand,
> CMH test is to test whether the common odds ratio
> (assuming odds ratios across stratum are equal) is
> equal to 1, not really the question I was asking which
> was whether the 2 odds ratios were equal (doesn't
> matter if they are equal to 1). Also, someone
> suggested loglinear regression, but I am not sure
> either how to set things up for my problem.
> 
> One clarification to my original email: the 2
> diagnostic tests were performed on the set set of
> patients, the issue here how to test whether the 2
> odds ratios for the 2 diagnostic tests are equal.
> 
> Here is a hypothetical dataset, for example:
> 
> dat<-
>
cbind(disease=sample(c(rep(1,15),rep(0,20))),test1=sample(c(rep(1,11),re
p(
> 0,24))),test2=sample(c(rep(1,14),rep(0,21))))
> 
> Hope some statistical experts would guide me some
> directions. Many thanks
> 
> **************************************