Many thanks, Tom and Howie!
Tom: Your solution worked beautifully, except for one tiny thing. I got a few people who weren't assigned to one of the three groups, and their codes all had one thing in common...an "indeterminate" test between their negative and positive tests:
hiv
......NI..PP
.....NIP....
......NI...P
I can very easily just recode these people to be incident seroconverters, but I wonder if there is an easy fix for the code that would do this automatically?
Howie: Many thanks for the explanation...that clears up a lot of my confusion!
BTW: my apologies if this post ends up in the wrong spot - I'm still trying to understand how to reply to individual postings when I receive Statalist in digest form...I'm hoping that slapping a "RE:" in front of the subject line I wish to respond to will allow me to do that, but I couldn't find information in the FAQ on specifically how to do this.
Cheers,
Chelsea
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