Re: OMEGA HAS A NONZERO BLOCK

From:Nick Holford Subject:Re: [NMusers] OMEGA HAS A NONZERO BLOCK Date: Wed, 09 Oct 2002 08:39:14 +1300 Leonid, If you believe that bioavailability is the ONLY source of variability for both CL and V then you will of course get a correlation of 1. But as I tried to explain previously we know from biological science that there are several identified fixed effects with different relationships (e.g. weight, age) for CL and V. Plus the unidentified fixed effects, which we treat as random effects, guarantee that the correlation cannot be one. So while it is true that the correlation of that component of ETA attributable to F can be expected to be 1 for CL and V this is not the only source of variability in these parameters and thus the overall correlaton must be less than 1. Nick ___________________________________