Howdy,
This is mostly a post to ask, is there an easier/more elegant way?
I would like to calculate odds ratios over pairs of stratification
variables, for example, hair and eyes. Hair has values of 0 or 1 and eyes
can be 0, 1, or 2. There are then 6 categories: hair = 0 and eyes = 0; hair
= 1 and eyes = 0; hair = 0 and eyes = 1; hair = 1 and eyes = 1 ...and so on.
The goal is a table that looks like this:
---------------------------------------------------------------------------
hair eyes | Odds Ratio chi2 P>chi2 [95% Conf. Interval]
-------------+----------------------------------------------------------
0 0 | 1.000000 . . . .
1 0 | 0.857143 0.02 0.8814 0.112836 6.511180
0 1 | 3.529412 2.23 0.1354 0.602837 20.663549
1 1 | 3.600000 2.39 0.1222 0.633331 20.463229
0 2 | 44.000000 16.95 0.0000 2.009823 963.268843
1 2 | 6.857143 4.72 0.0298 0.911312 51.596417
---------------------------------------------------------------------------
To achieve this result I currently use the following code:
gen cat = hair + 2*eyes
lab def catlbl 0 "0 0" 1 "1 0" 2 "0 1" 3 "1 1" 4 "0 2" 5 "1 2"
lab val cat catlbl
lab var cat "hair eyes"
tabodds cases cat, or base(1) // make sure we use hair = 0, eyes = 0 as the
referent
This code works but isn't portable. I have 3 primary variables to be
stratified over 8 other variables all with various possible values (ie some
are 0,1, and others are 0,1,2,3) yielding 24 combinations. Is there a
clever, portable way to generate variables representing all possible
combinations of two categorical variables? Or, better yet, a way to get
tabodds to stratify over two variables?
Thanks in advance to any thought given this problem,
Ben Hulley
*******************
NCI/DCEG/GEB
Room: EPS 7007
Tel: (301) 402-1622
Fax: (301) 402-4489
*
* 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/
