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

 From Richard Williams To statalist@hsphsun2.harvard.edu Subject Re: st: Interaction in Generalized Ordered Logistic regression_gologit2 (ORs and CIs) Date Wed, 18 May 2011 10:19:49 -0500

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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```