Time-to-event

From: michel.tod@avc.ap-hop-paris.fr (tod michel) Subject: Time-to-event Date: Mon, 30 Nov 1998 11:52:29 +0100 Dear NONMEM users, I have some questions about the analysis of time-to-event data with Weibull distribution using NONMEM version IV and the code described at the PKPD server: pkpd.icon.palo-alto.med.va.gov/nonmem.dir/NON_CONTINUOUS.DIR/ 1- What are the key assumptions that must be met when using the Weibull distribution for time-to-event? In other words, can this model be used, at least as an approximation, for all this kind of data type? (I recognize the restriction given by LB Sheiner that covariates have to be time-independent). 2- Are there restrictions about the value of Gamma (the exponent of (T/Tmedian))? Has it to be greater than 1? 3- Is the subroutine CCONTR identical to that used for random logistic regression (given in the same directory /NON_CONTINUOUS.DIR/)? 4- How can I simulate data for a working exemple of time-to-event data? Could anyone show me a control file for simulation of these kind of data? Thank you for your help. Michel Tod, PhD Dpt of Pharmacotoxicology Hopital Avicenne 93009 Bobigny FRANCE