Re: st: Logistic regression, changing order of variables

["Neil Shephard" <nshephard@gmail.com>]

On 6/22/07, Todd Swarthout <todd.swarthout@medecinsdumonde.net> wrote:
> Hello everyone.
>
> I am using logistic regression in the analysis of a database coming from
> a study in Zimbabwe.  A sample command is 'xi:logistic hiv i.age3 sexc
> age'
>
> The variable age3 is the age in 3 strata (2-4yrs, 5-11yrs, 12-17yrs). As
> I currently have the coding, 0=2-4yrs, 1=5-11yrs, and 2=12-17yrs. Thus
> the strata 2-4yrs is the point of comparison. In this case, the two
> older strata both showed a reduced risk of infection.
>
> However, I prefer to report the data in the context of which strata has
> increased risk of infection. Is there a command I can use (or add to the
> existing command 'xi:logistic hiv i.age3 sexc age') that would allow me
> to change the order of strata during logistic analysis. That is to say,
> if I want to use the 12-17 yr strata as the point of
> comparison...without having to create a new variable in which I change
> the coding.
See -man xi- pages under the heading "Summary of controlling the
omitted dummy" to alter which dummy variable is omitted and used as
reference.

Neil

--
"In mathematics you don't understand things. You just get used to
them."  - Johann von Neumann

Email - nshephard@gmail.com / n.shephard@sheffield.ac.uk
Website - http://slack.ser.man.ac.uk/
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