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Re: st: problem with predicted probabilities
From
Nick Cox <[email protected]>
To
"[email protected]" <[email protected]>
Subject
Re: st: problem with predicted probabilities
Date
Sun, 2 Feb 2014 10:19:50 +0000
As you want to use predicted probabilities in further work, use
-predict- to obtain them. -estat- here is just providing one report,
not the probabilities for future work. Start with -help logistic
postestimation-.
Nick
[email protected]
On 2 February 2014 09:58, Witness Chirinda <[email protected]> wrote:
> I want to obtain some predicted probabilities after logistic
> regression, as attached. I want to use the predicted probabilities in
> my next step instead of observed prevalence since the latter are
> adjusted for other (socio-demographic) factors.
> My problem is that the when I run - estat classification- it giving 0s
> for + classification. I am sure I am doing it the wrong way somewhere.
> Please see below output. All variables used in the model have been
> recorded to be binary 1/0
>
> Thanks for any help!
> ------------------
>
>
> . logistic Health_stat age maried wealth educat place sex
>
> Logistic regression Number of obs = 2339
> LR chi2(6)
> = 50.61
> Prob > chi2
> = 0.0000
> Log likelihood = -996.02516 Pseudo R2 = 0.0248
> ------------------------------------------------------------------------------
> Health_stat | Odds Ratio Std. Err. z P>|z| [95%
> Conf. Interval]
> -------------+----------------------------------------------------------------
> age | 1.109083 .0342696 3.35 0.001 1.043909 1.178326
> maried | 1.2134 .1962535 1.20 0.232 .8837556 1.666004
> Wealth | 1.430957 .1784661 2.87 0.004 1.120641 1.827203
> educat | 1.670411 .2010455 4.26 0.000 1.319397 2.11481
> place | .9334522 .1223134 -0.53 0.599 .7220318 1.206779
> sex | 1.129008 .1324642 1.03 0.301 .8970722 1.420911
>
> . estat class
>
> Logistic model for poorSRHS
> -------- True --------
> Classified | D ~D | Total
> -----------+--------------------------+-----------
> + | 0 0 | 0
> - | 370 1969 | 2339
> -----------+--------------------------+-----------
> Total | 370 1969 | 2339
>
> Classified + if predicted Pr(D) >= .5
> True D defined as poorSRHS != 0
> --------------------------------------------------
> Sensitivity Pr( +| D) 0.00%
> Specificity Pr( -|~D) 100.00%
> Positive predictive value Pr( D| +) .%
> Negative predictive value Pr(~D| -) 84.18%
> --------------------------------------------------
> False + rate for true ~D Pr( +|~D) 0.00%
> False - rate for true D Pr( -| D) 100.00%
> False + rate for classified + Pr(~D| +) .%
> False - rate for classified - Pr( D| -) 15.82%
> --------------------------------------------------
> Correctly classified 84.18%
> --------------------------------------------------
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