Posted by
Hector Maletta on
Aug 29, 2006; 3:34pm
URL: http://spssx-discussion.165.s1.nabble.com/Compare-odds-ratios-tp1070604p1070611.html
I suspect what you mean is whether the 0.487 odds ratio is significantly
different from 1. In other words, you want to know whether you can reject
the null hypothesis that a certain risk factor has no additional effect at
all compared with the reference situation. Is that so? I would not suspect
that with 0.487, except if my sample is really too small, but if the figure
is 0.98 the suspicion may be justifiable.
Hector
-----Mensaje original-----
De: SPSSX(r) Discussion [mailto:
[hidden email]] En nombre de Marta
García-Granero
Enviado el: Tuesday, August 29, 2006 11:25 AM
Para:
[hidden email]
Asunto: Re: Compare odds ratios
Hi Lou
Perhaps you havent' explained yourself completely... or I see an error
in your question: you just can't compare and odds-ratio with an odd,
and an OR from a group with the one of its reference group. I think
I'm being confused by the use of the term "reference group". Are you
talking about one qualitative variable that has been dummy coded, with
one group being the reference or is it something different?
L> Could someone please tell me the correct test to use to compare whether
L> two odds ratios are significantly different. For instance, I want to
L> compare the odds ratio for group A (odds ratio = 0.487) against the odds
L> ratio for the reference group (odds = 1).
--
Regards,
Dr. Marta García-Granero,PhD mailto:
[hidden email]
Statistician
---
"It is unwise to use a statistical procedure whose use one does
not understand. SPSS syntax guide cannot supply this knowledge, and it
is certainly no substitute for the basic understanding of statistics
and statistical thinking that is essential for the wise choice of
methods and the correct interpretation of their results".
(Adapted from WinPepi manual - I'm sure Joe Abrahmson will not mind)