[Date Prev][Date Next][Thread Prev][Thread Next][Date index][Thread index]
st: RE: Area under the curve trouble with aucdist
You might try -pkexamine-, Stata's built-in program
for such data.
> -----Original Message-----
> From: Joseph.Wagner2@med.va.gov [mailto:Joseph.Wagner2@med.va.gov]
> Sent: Tuesday, September 24, 2002 2:05 PM
> To: firstname.lastname@example.org
> Subject: st: Area under the curve trouble with aucdist
> I need to calculate the area under the curve (viral load over
> time) for
> about 1000 study participants using the trapezoidal rule. I have used
> aucdist but I am not getting a result and am not sure if I'm
> getting an
> error message.
> id = patient id
> time = time of viral load test
> conc = viral load value
> aucdist id time conc, t generate(auc)
> (t specifies that the integral be computed using the simple
> rule, and generate(auc) specifies to create a new variable
> with the AUC (C
> max, T max, log conc 0 -inf.))
> but all I'm getting is (2000) in return which is supposed to
> mean that I
> have no observations on which to perform the statistical operation.
> I have 9500 observations with multiple observations per
> patient, there are
> no missing data. Any suggestions as to what I may be doing wrong?
> * 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/
CONFIDENTIALITY NOTE: This e-mail message, including any attachment(s), contains information that may be confidential, protected by the attorney-client or other legal privileges, and/or proprietary non-public information. If you are not an intended recipient of this message or an authorized assistant to an intended recipient, please notify the sender by replying to this message and then delete it from your system. Use, dissemination, distribution, or reproduction of this message and/or any of its attachments (if any) by unintended recipients is not authorized and may be unlawful.