Re: st: Interaction in Generalized Ordered Logistic regression_gologit2 (ORs and CIs)

[Richard Williams <richardwilliams.ndu@gmail.com>]

If I understand the question, I believe you would do this the same 
way as you would if you were using mlogit. Something like

use "http://www.indiana.edu/~jslsoc/stata/spex_data/ordwarm2.dta";, clear
gen yr89ed = yr89 * ed
gologit2  warm yr89 male white age ed prst  yr89ed, npl(yr89ed) lrf
forvalues i = 1/3 {
lincom [#`i']ed + [#`i']yr89ed, or
}

The key thing is you have to specify the equation #s for lincom; 
otherwise it only does the first one.


At 04:29 AM 5/18/2011, Sanam P wrote:
> Dear Stata list
>
> I have done a partial proportional odds regression (Generalized 
> Ordered Logistic
> Regression) using gologit2 command with most of categorical variables having
> more than 2 categories:
>
> xi: gologit2   y  i.a   i.b  i.c, autofit(0.01) lrforce or
>
>  I would like to include interaction terms between one of the 
> covariates which
> has 2 categories with other covariates in the model.
>
> Like other regression models I have tested for significance of the 
> interactions
> using Likelihood Ratio tests:
>
> e.g.:
> xi: gologit2   y  i.a *i.b  i.c, autofit(0.01) lrforce or
>  eststore A
> xi: gologit2   y  i.a i.b  i.c, autofit(0.01) lrforce or
>  eststore B
>  lrtestA B
>
>  For the interactions that are significant, I would like to have the ORs and
> Confidence intervals for the effect of variables included in the 
> interaction in
> each panel.
>
> In other regression models it is possible to calculate for example Hazards
> Ratios and confidence intervals for the interactions, using Lincom command.
>
> for example for the effect of age in stages 2 and 3 of cancer (Hrs and CIs),
> after running the model using stcox:
> **effect of age for stage 2
>  lincom age+ _IstaXage_d_2,hr
> **effect of age for stage 3
>  lincom age+ _IstaXage_d_3,hr
>
> However in Generalized Ordered model there are more than one OR for each
> covariate (depending on the number of levels of the outcome variable 
> which will
> determine number of the panels), and lincom command will give only one OR and
> one CI for each variable's effect..
>
> I would really appreciate it if you could help me on how I can have 
> the ORs and
> CIs for the effect of the variables included in the interaction terms for all
> the panels in the generalized Ordered Logistic model in stata 11.
>
> *
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-------------------------------------------
Richard Williams, Notre Dame Dept of Sociology
OFFICE: (574)631-6668, (574)631-6463
HOME:   (574)289-5227
EMAIL:  Richard.A.Williams.5@ND.Edu
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*
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