st: tables to include columns for observations that are not present

["Christopher W. Ryan" <cryan@binghamton.edu>]

I am trying to use Stata to monitor and analyze the types of encounters 
that my medical students see in their family medicine course.  I use 
ICPC-2 diagnostic codes to classify the encounters (International 
Classification of Primary Care).

I have a dataset with the following variables:
studentid
code
textforcode
count

It is easy enough to generate a table with students in rows down the 
side, and the ICPC codes in columns across the top, with the cells 
containing the number of times a student has seen that diagnosis:

-table studentid code, contents(sum count)-

My trouble arises with codes that *no* student has seen.  With the 
simple table-related commands with which I'm familiar, no column for 
such a code will appear in the table.  But there are 10 diagnostic codes 
that I need to monitor, to make sure every student has encountered at 
least one case of them.  So I'd like columns for those ten codes to 
always appear in the table, irrespective of whether anyone saw those 
diagnoses.  If no one has seen one of those diagnoses, then the cells in 
that column would all contain the number zero.

Any suggestions how to do this?

Thanks.
--
Christopher W. Ryan, MD
SUNY Upstate Medical University Clinical Campus at Binghamton
and Wilson Family Practice Residency, Johnson City, NY
cryanatbinghamtondotedu
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