# st: Analyzing a subpopulation in Stata 10.1

 From "Karadogan, Figen" <[email protected]> To "[email protected]" <[email protected]> Subject st: Analyzing a subpopulation in Stata 10.1 Date Fri, 26 Jun 2009 16:42:43 +0000

``` Hello,

I do apologize for the attachment, but given the complexity of the question I would like to provide you all the information I have.

Please find the result of my output attached. There, I would like to find out the proportion of diabetics older than 25yrs old, who go to dentist by education.  The N of cases jointly non-missing on diabetes (dmrc_dum), dentist  (dentistrc), age older than 25 (agerc25), education  (edurc) is 3772. The N of cases jointly non-missing on diabetes and dentist is 3783.

I know that Stata needs information from every observation in the sample to compute the variance, standard error and confidence intervals even though only the information in the subsamples is needed to compute proportions.  But, I am confused which one of those syntaxes gives me the correct total number of observations = 3772 or 3783??

Thank you very much for your help.