Thanks, Nick. That -cmd- option is handy. You gotta love those undocumented
options. The -by- works perfectly using -glm-.
Best,
Lee Sieswerda
> -----Original Message-----
> From: Nick Winter [SMTP:[email protected]]
> Sent: Wednesday, December 04, 2002 3:44 PM
> To: [email protected]
> Subject: st: RE: -by- with -binreg-
>
> Looking at the ado code for -binreg-, it seems that -binreg- is a
> wrapper for -glm-, and that the call to -glm- does not preserve the "by
> varlist:" that you specify.
>
> This should be a quick thing for SstataCorp to fix. In the mean time,
> you can just call -glm- directly, which does properly support "by
> varlist:". The (undocumented?) "cmd" option of -binreg- seems to tell
> you the necessary -glm- syntax.
>
> Nick Winter
>
> > -----Original Message-----
> > From: Lee Sieswerda [mailto:[email protected]]
> > Sent: Wednesday, December 04, 2002 3:31 PM
> > To: Statalist (E-mail)
> > Subject: st: -by- with -binreg-
> >
> >
> > Dear Statalisters:
> > For some reason I cannot get -by- to work with -binreg-. I
> > can get around
> > the problem using -if-, but according to the manual I should
> > be able to use
> > -by-. Here is my log:
> >
> > . table pre_post sex, c(mean q7cat)
> >
> > ------------------------------
> > | sex
> > pre_post | F M
> > ----------+-------------------
> > pre | .3238095 .4953271
> > post | .6 .6296296
> > ------------------------------
> >
> > * Both sexes together
> > . binreg q7cat pre_post, rd cluster(id)
> >
> > Iteration 1 : deviance = 570.9529
> > Iteration 2 : deviance = 570.9529
> >
> > Residual df = 423 No. of obs =
> > 425
> > Pearson X2 = 425 Deviance =
> > 570.9529
> > Dispersion = 1.004728 Dispersion =
> > 1.349771
> >
> > Bernoulli distribution, identity link
> > Risk difference coefficients
> > (standard errors adjusted for
> > clustering on
> > id)
> > --------------------------------------------------------------
> > --------------
> > --
> > | Semi-Robust
> > q7cat | Coef. Std. Err. z P>|z| [95% Conf.
> > Interval]
> > -------------+------------------------------------------------
> > --------------
> > --
> > pre_post | .2046461 .0391639 5.23 0.000 .1278862
> > .281406
> > _cons | .2057312 .0651479 3.16 0.002 .0780438
> > .3334187
> > --------------------------------------------------------------
> > --------------
> > --
> >
> > * Try to get separate estimates by sex
> >
> > . bysort sex: binreg q7cat pre_post, rd cluster(id)
> >
> > ______________________________________________________________
> > ______________
> > ___
> > -> sex = F
> >
> > Iteration 1 : deviance = 570.9529
> > Iteration 2 : deviance = 570.9529
> >
> > Residual df = 423 No. of obs =
> > 425
> > Pearson X2 = 425 Deviance =
> > 570.9529
> > Dispersion = 1.004728 Dispersion =
> > 1.349771
> >
> > Bernoulli distribution, identity link
> > Risk difference coefficients
> > (standard errors adjusted for
> > clustering on
> > id)
> > --------------------------------------------------------------
> > --------------
> > --
> > | Semi-Robust
> > q7cat | Coef. Std. Err. z P>|z| [95% Conf.
> > Interval]
> > -------------+------------------------------------------------
> > --------------
> > --
> > pre_post | .2046461 .0391639 5.23 0.000 .1278862
> > .281406
> > _cons | .2057312 .0651479 3.16 0.002 .0780438
> > .3334187
> > --------------------------------------------------------------
> > --------------
> > --
> >
> > ______________________________________________________________
> > ______________
> > ___
> > -> sex = M
> >
> > Iteration 1 : deviance = 570.9529
> > Iteration 2 : deviance = 570.9529
> >
> > Residual df = 423 No. of obs =
> > 425
> > Pearson X2 = 425 Deviance =
> > 570.9529
> > Dispersion = 1.004728 Dispersion =
> > 1.349771
> >
> > Bernoulli distribution, identity link
> > Risk difference coefficients
> > (standard errors adjusted for
> > clustering on
> > id)
> > --------------------------------------------------------------
> > --------------
> > --
> > | Semi-Robust
> > q7cat | Coef. Std. Err. z P>|z| [95% Conf.
> > Interval]
> > -------------+------------------------------------------------
> > --------------
> > --
> > pre_post | .2046461 .0391639 5.23 0.000 .1278862
> > .281406
> > _cons | .2057312 .0651479 3.16 0.002 .0780438
> > .3334187
> > --------------------------------------------------------------
> > --------------
> > --
> >
> > * Since that gave the same results as if I hadn't used
> > * -by- at all, try -if- instead
> >
> > . binreg q7cat pre_post if sex=="M", rd cluster(id)
> >
> > Iteration 1 : deviance = 290.7011
> > Iteration 2 : deviance = 290.7011
> >
> > Residual df = 213 No. of obs =
> > 215
> > Pearson X2 = 215 Deviance =
> > 290.7011
> > Dispersion = 1.00939 Dispersion =
> > 1.364794
> >
> > Bernoulli distribution, identity link
> > Risk difference coefficients
> > (standard errors adjusted for
> > clustering on
> > id)
> > --------------------------------------------------------------
> > --------------
> > --
> > | Semi-Robust
> > q7cat | Coef. Std. Err. z P>|z| [95% Conf.
> > Interval]
> > -------------+------------------------------------------------
> > --------------
> > --
> > pre_post | .1343025 .0536422 2.50 0.012 .0291657
> > .2394394
> > _cons | .3610246 .0910578 3.96 0.000 .1825546
> > .5394945
> > --------------------------------------------------------------
> > --------------
> > --
> >
> > . binreg q7cat pre_post if sex=="F", rd cluster(id)
> >
> > Iteration 1 : deviance = 273.5711
> > Iteration 2 : deviance = 273.5711
> >
> > Residual df = 208 No. of obs =
> > 210
> > Pearson X2 = 210 Deviance =
> > 273.5711
> > Dispersion = 1.009615 Dispersion =
> > 1.315246
> >
> > Bernoulli distribution, identity link
> > Risk difference coefficients
> > (standard errors adjusted for
> > clustering on
> > id)
> > --------------------------------------------------------------
> > --------------
> > --
> > | Semi-Robust
> > q7cat | Coef. Std. Err. z P>|z| [95% Conf.
> > Interval]
> > -------------+------------------------------------------------
> > --------------
> > --
> > pre_post | .2761905 .0566061 4.88 0.000 .1652445
> > .3871365
> > _cons | .047619 .0911676 0.52 0.601 -.1310661
> > .2263042
> > --------------------------------------------------------------
> > --------------
> > --
> >
> > * Suppose I use -regress- instead of -binreg-. Then can I use -by-?
> > . by sex: regress q7cat pre_post, cluster(id)
> >
> > ______________________________________________________________
> > ______________
> > ___
> > -> sex = F
> >
> > Regression with robust standard errors Number of obs =
> > 210
> > F( 1, 104) =
> > 23.69
> > Prob > F =
> > 0.0000
> > R-squared =
> > 0.0767
> > Number of clusters (id) = 105 Root MSE =
> > .48134
> >
> > --------------------------------------------------------------
> > --------------
> > --
> > | Robust
> > q7cat | Coef. Std. Err. t P>|t| [95% Conf.
> > Interval]
> > -------------+------------------------------------------------
> > --------------
> > --
> > pre_post | .2761905 .0567421 4.87 0.000 .1636688
> > .3887121
> > _cons | .047619 .0913865 0.52 0.603 -.1336038
> > .2288419
> > --------------------------------------------------------------
> > --------------
> > --
> >
> > ______________________________________________________________
> > ______________
> > ___
> > -> sex = M
> >
> > Regression with robust standard errors Number of obs =
> > 215
> > F( 1, 108) =
> > 6.24
> > Prob > F =
> > 0.0140
> > R-squared =
> > 0.0183
> > Number of clusters (id) = 109 Root MSE =
> > .49378
> >
> > --------------------------------------------------------------
> > --------------
> > --
> > | Robust
> > q7cat | Coef. Std. Err. t P>|t| [95% Conf.
> > Interval]
> > -------------+------------------------------------------------
> > --------------
> > --
> > pre_post | .1343025 .053768 2.50 0.014 .027725
> > .2408801
> > _cons | .3610246 .0912713 3.96 0.000 .1801091
> > .5419401
> > --------------------------------------------------------------
> > --------------
> > --
> >
> > So in this case -regress- works with -by-, but -binreg- does
> > not. I also
> > have sex as a numeric variable, but that doesn't alleviate
> > the non-working
> > -by- (NPI). Any ideas?
> >
> > Regards,
> > Lee
> >
> > Lee Sieswerda, Epidemiologist
> > Thunder Bay District Health Unit
> > 999 Balmoral Street
> > Thunder Bay, Ontario
> > Canada P7B 6E7
> > Tel: +1 (807) 625-5957
> > Fax: +1 (807) 623-2369
> > [email protected]
> > www.tbdhu.com
> >
> > *
> > * For searches and help try:
> > * http://www.stata.com/support/faqs/res/findit.html
> > * http://www.stata.com/support/statalist/faq
> > * http://www.ats.ucla.edu/stat/stata/
> >
> *
> * For searches and help try:
> * http://www.stata.com/support/faqs/res/findit.html
> * http://www.stata.com/support/statalist/faq
> * http://www.ats.ucla.edu/stat/stata/
*
* For searches and help try:
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