NonMem and EVID=2

From: Johan Rosenborg Date: April 23, 2019 technical Source: mail-archive.com
Hello everybody, In order to obtain predicted values in a PopPK analysis without covariates at points in time with no actual values I have inserted extra rows indicated with EVID=2. The covariance step is completed when including these extra rows and precision of the parameter estimates are adequate. When omitting the extra rows {IGNORE=(EVID.EQ.2)}, I get exactly the same parameter estimates, the covariace step can be completed with some difficulty, but precision of the parameter estimates are now inadequate. I use METHOD=1 and just like Ahmed Abbas Suleiman experienced ( https://cognigencorp.com/nonmem/current/2013-February/4440.html 2 https://cognigencorp.com/nonmem/current/2013-February/4440.html), my outcome did not differ between the two conditions when setting METHOD=0. I saw that William Denney has responded to a similar question in 2016 ( https://cognigencorp.com/nonmem/current/2016-February/6085.html 2 https://cognigencorp.com/nonmem/current/2016-February/6085.html). I cannot see any response to Ahmed’s comment; do you Bill or somebody else have any idea why the outcomes differ with METHOD=1 but not with METHOD=0 in NonMem when including extra rows in the data set? Thank you in advance and kind regards, Johan
Apr 23, 2019 Johan Rosenborg NonMem and EVID=2
Apr 23, 2019 Bill Denney RE: NonMem and EVID=2
Apr 23, 2019 Jeroen Elassaiss-Schaap Re: NonMem and EVID=2