1 simple question from a nmbeginner

2 messages 2 people Latest: Oct 13, 2003

1 simple question from a nmbeginner

From: Yilong Zhang Date: October 12, 2003 technical
From: zhang.239@osu.edu Subject: [NMusers] 1 simple question from a nmbeginner Date: 10/12/2003 11:43 PM Dear all, I have 1 simple question: From NONMEM menu, I know that a decrease in OFV higher than 3.8 was required to incorporate a covariate into the model. In one data set, I found that the OFV decreased from -320 to -330 after incorporated BSA to the model. Can anybody let me know how important this change (3%) is? Thanks! Yilong Zhang

RE: 1 simple question from a nmbeginner

From: William Bachman Date: October 13, 2003 technical
From: bachmanw@globomax.com Subject: RE: [NMusers] 1 simple question from a nmbeginner Date: 10/13/2003 8:56 AM The % change is meaningless. The criterion for inclusion/exclusion is based on your chosen signifigance level, the degrees of freedom and the critical chi square value (for sig. level and df). Also, change in objective function should not be the only criterion for acceptance. You should also consider the change in variance estimates and the diagnostic plots before accepting the new model. _______________________________________________________