st: Combining multiple survey data sets

[James Swartz <jaswartz@uic.edu>]

All,

I searched for information on this topic and found a bit in archived 
threads, but not as much detail as I need. So at the risk of some 
redundancy, I would like to ask for help from a sampling statistician 
out there who also knows Stata well and who has worked with multiple 
survey data sets:

I am using two data sets. One is the National Comorbidity Survey 
Replication (NCS-R) and the other is a data set based on data I 
collected locally using the same instrument as the NCS-R. The N's are 
very different: the NCS-R part 2 is around 5,000 to 6,000 cases and my 
data set has only about 450 cases.  Each data set has different survey 
parameters. I have no PSUs but do have stratification on gender and I 
developed weights to account for non-coverage and non-response. The 
NCS-R data set includes variables for weights, strata, and PSUs.  Here 
are my questions:

1) In a simple bivariate analysis, I want to compare the prevalences of 
chronic medical conditions in each data set. But how can I tell Stata to 
use one set of survey parameters for cases in the NCS-R and another for 
cases in my local data set? Also, how important is it to control for a 
finite population correction factor?  I have not done this in any 
analyses previously.

2) In a second step, I used the PSMATCH2 add-on to create a matched 
sample of 450 cases from the NCS-R data set based on a selected set of 
demographics and other characteristics. I then want to fun logistic 
regressions on the odds of having a chronic medical conditions while 
controlling for the matching variables (the matches were not perfect) 
and other unmatched characteristics. I assume that at this point, the 
survey parameters are not applicable because there is no way (that I can 
figure) to apply the subpopulation option. Is that correct?  Is this 
analytic model reasonable given the data sets available or would there 
be a better way to approach this problem?

Thanks for any help. I have been scratching my head on this one for awhile.

James

--

James Swartz, Ph.D., Associate Professor
Jane Addams College of Social Work, University of Illinois at Chicago
1040 W. Harrison Street (MC 309)
Chicago IL. 60607

http://www.uic.edu/jaddams/college/subabuse/

P 312-996-8560
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E (W): jaswartz@uic.edu
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"That which stands in the way of our work, is our work."
        - Marcus Aurelius

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