[R] Odds ratio from Logistic model in R

[Joshua Wiley]

Hi Guoya,

Is this what you are after?

# fit logistic model
my.glm <- glm(vs ~ mpg, data = mtcars, family = binomial(link = "logit"))

# look at a summary
summary(my.glm)

# view the coefficients as odds ratios
exp(coef(my.glm))

Hope that helps,

Josh

On Fri, Sep 24, 2010 at 10:50 AM, Li, Guoya <Guoya_Li at bshsi.org> wrote:
> Hi, I am new to R. Anyone can explain the following from R-help or
> anyone can direct me how to calculate odds ratio from logistic model in
> R. Thank you very much. Guoya
>
>
>
>
>
> Stefano <stecalza at tiscalinet.it
> <https://stat.ethz.ch/mailman/listinfo/r-help> > writes:
>>Hi all.
>>
>>A simple question.
>>Is there a function to compute the Odds Ratio and its confidence
> intervall, from
>>a logistic model (glm(.......,family=binomial....). I've written my
> own, but
>>certainly someone did a better job.
>
> I show a simple function to do this in my introductory notes available
> from:
>
>        http://www.myatt.demon.co.uk
>
> basically it is:
>
>        lreg.or <- function(model)
>          {
>          lreg.coeffs <- coef(summary(salex.lreg))
>          lci <- exp(lreg.coeffs[ ,1] - 1.96 * lreg.coeffs[ ,2])
>          or <- exp(lreg.coeffs[ ,1])
>          uci <- exp(lreg.coeffs[ ,1] + 1.96 * lreg.coeffs[ ,2])
>          lreg.or <- cbind(lci, or, uci)
>          lreg.or
>          }
>
>
>
>
>
>        [[alternative HTML version deleted]]
>
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> and provide commented, minimal, self-contained, reproducible code.
>



-- 
Joshua Wiley
Ph.D. Student, Health Psychology
University of California, Los Angeles
http://www.joshuawiley.com/