# RE: st: odds ratio vs. RRR in multinomial logistic regression

 From Michelle To statalist@hsphsun2.harvard.edu Subject RE: st: odds ratio vs. RRR in multinomial logistic regression Date Wed, 10 Aug 2005 12:40:29 -0700 (PDT)

```Some of the statalist members were kind enough to
respond to my inquiry a few months ago about
interpreting multinomial logistic regression and the
resulting RRR.

"For the RRR it would be, for example, 'the relative
risk of outcome 3 associated with X is 0.85 times
the relative risk of outcome 1 associated with X'."

This was helpful, but when I wrote it up in my
dissertation this way, my advisor has told me that I
need to put it in "plain English." Can anyone help me
put this sentence into more interpretable language for
someone who is not very familiar with RRR?

where the RRR comes from and then followed it with the
results reported as above, but my advisor is still
requiring a more intuitive or interpretable sentence.

Thank you very much.

--- David Harrison <david.harrison@icnarc.org> wrote:

> I think your interpretation of the odds ratio is
> wrong. It should be "the odds of outcome 1 given X
> is true are 2.4 times greater than the odds of
> outcome 1 given X is not true."
>
> For the RRR it would be, for example, "the relative
> risk of outcome 3 associated with X is 0.85 times
> the relative risk of outcome 1 associated with X."
>
> David
>
> -----Original Message-----
> From: Michelle [mailto:cantibridgian@yahoo.com]
> Sent: 03 June 2005 14:16
> To: statalist@hsphsun2.harvard.edu
> Subject: RE: st: odds ratio vs. RRR in multinomial
> logistic regression
>
>
> Thanks - this is very helpful. One more question:
>
> With odds ratios in binary logistic regression, you
> can easily interpret the exponentiated coefficient
> by
> stating that "the odds of outcome 1 are 2.4 times
> greater than the odds of outcome 2."
>
> When I expoentiate the coefficient in multinomial
> logistic regression (or use the RRR that is
> provided),
> I can obviously say "the RRR is .85". But is there
> some more easily interpretable way that I can
> describe
> what this number means, as one could do in binary
> logistic regression? For instance, can I make a
> statement about the probability of outcomes 3 as
> compared to outcome 1?
>
> Thanks again.
>
>
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