Yaming,
You may wish to consult this document for details of coding time to
event models using NM-TRAN.
http://holford.fmhs.auckland.ac.nz/docs/time-to-event-webinar.pdf
It is really very simple to integrate the hazard numerically using $DES.
If you are dealing with only one event per subject then there are no
random effects to be estimated in the model and it will run quite
quickly with the FO estimation method.
Best wishes,
Nick
On 4/04/2013 9:35 a.m., Yaming Hang wrote:
Dear NONMEM Users,
I have some questions about how to accomplish the following tasks in
NONMEM, would you kindly share your experience with me or provide some
suggestions? I’m trying to make a simulation that involves dynamic
dosing. Here is the algorithm of simulation: at time 0, a dose is
given, then the time to the first event will be simulated based on a
certain survival function which depends on the drug exposure. Next,
conditioning on that simulated first event time, a second dose will be
introduced, and again time to the second event will be simulated. This
will be repeated until a certain cut off time point.
My specific questions are:
1. since the dosing history will be depending on the simulated event
time, I cannot construct the dosing history in NONMEM data set a
prior, how can this be done?
2. The survival function is a function of the time-varying drug
exposure, therefore I need to inverse an integral which does not have
a closed form (i.e. only expressed in differential equation), how can
I do that?
Your help will be much appreciated!
Yaming Hang
--
Nick Holford, Professor Clinical Pharmacology
Dept Pharmacology & Clinical Pharmacology, Bldg 503 Room 302A
University of Auckland,85 Park Rd,Private Bag 92019,Auckland,New Zealand
tel:+64(9)923-6730 fax:+64(9)373-7090 mobile:+64(21)46 23 53
email: [email protected]
http://www.fmhs.auckland.ac.nz/sms/pharmacology/holford
