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Re: st: Interval censored survival and stpm or intcens
Sharon, to use -intcens- you should create another data set with the
proper variables and without multiple observations. If you need help
doing this, just ask.
We cannot answer your question about why -stpm- is not working if you
do not show the statements you used and the complete output with
actual error statements. To quote the list FAQ): "Say exactly what
you typed and exactly what Stata typed (or did) in response. N.B.
exactly! If you can, reproduce the error with one of Stata's provided
datasets or a simple concocted dataset that you include in your
posting."
-Steven
On Sep 7, 2007, at 12:42 AM, Sharon Minnick wrote:
Hello,
I have been attempting to analyze my interval censored survival
data with either stpm or intcens ado's (From SSC). Both programs
have been used in published papers (stpm: Royston and Parmar 2002;
intcens: Griffin et al 2006). However, unless I am missing
something, they don't seem able to handle multiple records per
subject. In my study, subjects are bled and their serology
checked at 6 month intervals. I want to be able to use the
intervals when they were negative (and at risk) as well as the
interval ending in seroconversion (or censoring) and I don't want
to make only one interval per subject where some intervals will
then be 2 or 3 years long. Does anyone have experience using either
of these ado's in such a situation?
My data is in the span format with multiple records per subject.
For each subject, _t0 is the first date of the span and _t is the
second date of the span. There are no gaps, so _t for the first
span is equal to _t0 for the second span.
In the intcens ado, the interval is specified as t0 and t1, there
is no subject identifier. Intcens does not use stset parameters so
I would lose some of the structure of my data.
For stpm, I have tried to define the left variable to specify that
the observations are interval-censored by using _t0 as the left
variable (which is < _t so according to the help file, when _d is
0, this will specify late entry at _t0 and right censoring at _t
and when d is 1, this will specify interval censoring with an event
in [_t0, _t]. I always receive the error message "
If anyone has used these ado files with interval censored data with
multiple records per subject, I would appreciate a note as to
whether or not it worked (and how to set it up).
Thanks!
Sharon Minnick
University of California at Davis
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Steven Samuels
[email protected]
18 Cantine's Island
Saugerties, NY 12477
Phone: 845-246-0774
EFax: 208-498-7441
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* 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/