Notice: On April 23, 2014, Statalist moved from an email list to a forum, based at statalist.org.
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
st: problem with predicted probabilities
From
Witness Chirinda <[email protected]>
To
[email protected]
Subject
st: problem with predicted probabilities
Date
Sun, 2 Feb 2014 11:58:46 +0200
Dear Statalist
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%
--------------------------------------------------
*
* For searches and help try:
* http://www.stata.com/help.cgi?search
* http://www.stata.com/support/faqs/resources/statalist-faq/
* http://www.ats.ucla.edu/stat/stata/