Log Normal data

From: "David Nix" <nix@pharmacy.arizona.edu> Subject: Log Normal data Date: 29 Oct 1997 13:01:58 -0500 Is there any way to force NONMEM to use a log-normal distribution for the intersubject variability involving PK parameters? The only way that I can come up with is to: 1. Enter concentration data as log transformed values DV=LN (conc) 2. Model Y=Log(F) + EPS(1) Is this valid? Is there any way to evaluate whether a log-normal or normal distribution provides the best goodness of fit for a given data set within NONMEM? I assume that if the strategy above is correct, I would not be able to compare objective functions between the analysis of log transformed data and untransformed data. This issue came up because I am working with a data set that was previously analysed as individual subjects. The PK parameters determined by individual analysis is clearly log-normally distributed. Is it acceptable to use a normal distribution for intersubject error in NONMEM?