Notice: On April 23, 2014, Statalist moved from an email list to a forum, based at statalist.org.
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
st: calculating AUROC when odds ratio cannot be defined
From
Ashwin Ananthakrishnan <[email protected]>
To
[email protected]
Subject
st: calculating AUROC when odds ratio cannot be defined
Date
Mon, 16 May 2011 08:24:37 -0700 (PDT)
Hi,
I'm trying to calculate the area under the ROC for a model where the outcome is
binary (disease 1 vs. disease 2) and the predictors are response rates at
various time points (also binary variables - for example, response at 2 months -
Y/N, response at 3 months - Y/N).
For the 3 month cut off point, all patients with disease 1 respond (100%) while
about 40% of those with disease 2 respond. Obviously, I can't calculate an odds
ratio for this time point. Is it possible to calculate an AUROC with disease 1
vs. disease 2 as the outcome of interest and response at 3 months as the
predictor variable? Or because there are no events in one of the 2x2 boxes, is
it that an AUROC cannot be calculated?
Thanks,
Ashwin
*
* For searches and help try:
* http://www.stata.com/help.cgi?search
* http://www.stata.com/support/statalist/faq
* http://www.ats.ucla.edu/stat/stata/