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

[Sanam P <sanamp25@yahoo.com>]

Dear Richard

I would like to thank you very much for your response to my questions on this, 
here and off line. It was really helpful and I really appreciate it.

Kind regards,

 


----- Original Message ----
From: Richard Williams <richardwilliams.ndu@gmail.com>
To: statalist@hsphsun2.harvard.edu
Sent: Wed, May 18, 2011 8:19:49 AM
Subject: Re: st: Interaction in Generalized Ordered Logistic regression_gologit2 
(ORs and CIs)

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.
>
>*
>*  For searches and help try:
>*  http://www.stata.com/help.cgi?search
>*  http://www.stata.com/support/statalist/faq
>*  http://www.ats.ucla.edu/stat/stata/

-------------------------------------------
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
WWW:    http://www.nd.edu/~rwilliam

*
*  For searches and help try:
*  http://www.stata.com/help.cgi?search
*  http://www.stata.com/support/statalist/faq
*  http://www.ats.ucla.edu/stat/stata/


*
*   For searches and help try:
*   http://www.stata.com/help.cgi?search
*   http://www.stata.com/support/statalist/faq
*   http://www.ats.ucla.edu/stat/stata/