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Re: odds ratio to chi square conversion

Posted by Rich Ulrich on Jun 29, 2012; 2:58pm
URL: http://spssx-discussion.165.s1.nabble.com/odds-ratio-to-chi-square-conversion-tp5713894p5713898.html

No.  You need both sets of marginal totals to convert
an OR to a chi squared.  You can show this by taking a
fixed total-N and constructing various tables with the
same OR and different tests.

For the meta-analysis:  after making sure that the
information really is not there, contact the authors.
They probably will oblige.

A worthwhile meta-analysis is seldom easy.  It wants
expertise both in statistics and in the content, so, good luck.

--
Rich Ulrich

> Date: Fri, 29 Jun 2012 09:45:35 -0400
> From: [hidden email]
> Subject: odds ratio to chi square conversion
> To: [hidden email]
>
> Is there a way to convert an odds ratio to a chi square value? Specifically, given a 2x2 crosstabulation of x against y, the association between x and y can be expressed as an odds ratio (OR: bc/ad), as exp(B) from a logistic regression or a chi square. Knowing only either OR or B, can a chi-square be computed? One of the places this problem comes up is in meta-analyses where authors don't report sufficient data in primary reports.
>
> Thanks, Gene Maguin
> ...