st: Re: Test equality of predictors after logistic regression

[Debs Majumdar <debs_stata@yahoo.com>]

Pressed enter too soon.

I think  
test  score_v1 score_v2 score_v3 score_v4 


 ( 1)  [status]score_v1 = 0
 ( 2)  [status]score_v2 = 0
 ( 3)  [status]score_v3 = 0
 ( 4)  [status]score_v4 = 0

           chi2(  4) =   11.86
         Prob > chi2 =    0.0185



tests if the coefficients of the four scores are simultaneously equals to zero with 4 degrees of freedom..


whereas if I want to test if the four scores are equal or not, then I would just do


test  score_v1=score_v2=score_v3=score_v4 

which will test

( 1)  [status]score_v1 - [status]score_v2 = 0
 ( 2)  [status]score_v1 - [status]score_v3 = 0
 ( 3)  [status]score_v1 - [status]score_v4 = 0

           chi2(  3) =    9.57
         Prob > chi2 =    0.0276


Am I right here?

 Thanks




----- Original Message -----
From: Debs Majumdar <debs_stata@yahoo.com>
To: "statalist@hsphsun2.harvard.edu" <statalist@hsphsun2.harvard.edu>
Cc: 
Sent: Monday, September 24, 2012 9:36 PM
Subject: Test equality of predictors after logistic regression

Hi All,

 I ran the following logistic regression:

logit status score_v1 score_v2 score_v3 score_v4  c1-c3   site1 - site14


I am supposed to test if the effects of the four scores (v1-v4) are different or not?


 Should I just run 

test  score_v1 score_v2 score_v3 score_v4   


after running the logistic regression?

Thanks,

Debs

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