Re: TVKa>TVKe or Ka>Ke?

From: Nick Holford <n.holford@auckland.ac.nz> Subject: Re: [NMusers] TVKa>TVKe or Ka>Ke? Date: 8/7/2003 4:14 PM Hi, There is a simpler method than constructing special parameterizations at the population or individual level. It was mentioned earlier in this thread but was not discussed ie. use of an EXIT statement CL=THETA(cl)*EXP(ETA(cl)) V=THETA(v)*EXP(ETA(v)) K=CL/V KA=THETA(ka)*EXP(ETA(ka)) IF (KA.LE.K) EXIT 1 101 ; try again (PREDERR message error code 101) This is really no different than using the NOABORT option and letting NONMEM catch instances of CL, V, F etc that are <=0. It is of course implicitly modifying the distributions of CL,V,KA in some way to ensure KA>K but should we care about this? The only situation that comes to mind would be if one tried to simulate from the parameter estimates. But in any case I would probably want to truncate the simulated parameters in the same way to avoid flip-flop. Nick -- Nick Holford, Dept Pharmacology & Clinical Pharmacology University of Auckland, 85 Park Rd, Private Bag 92019, Auckland, New Zealand email:n.holford@auckland.ac.nz tel:+64(9)373-7599x86730 fax:373-7556 http://www.health.auckland.ac.nz/pharmacology/staff/nholford/