Re: NONMEM

From: "Stephen Duffull" stephen.duffull@stonebow.otago.ac.nz Subject: Re: [NMusers] NONMEM Date: Fri, 15 Sep 2006 09:25:45 +1200 Mark >> I agree with Steve, optimal design for studies is not >> generally available. Instead, we use simulation, to >> plagarize Steves term, to find a sufficient design by >> tweaking parameters and doing MC simulation. I would >> however, suggest that given sufficient computational power, >> formal optimization is possible on a reasonable >> time line - a couple of days. I would suggest that using a information theoretic technique you would get rid of the simulation component completely and do this more efficiently using an FIM approach. I do not advocate simulation where quicker methods are available. If you use simulation then: 1) how do you know what designs to choose? 2) how do you determine when you have a minimally effective design - could there be another design around the corner that you didn't think of which is more efficient? Why not just let an FIM search do its business, get the answer for the most efficient-sufficient design. In a sense the most efficient design is how you would determine 'optimal' (or 'best') - just that the design is cast from finding the minimum experimental effort rather than some other goal. Steve -- Professor Stephen Duffull Chair of Clinical Pharmacy School of Pharmacy University of Otago PO Box 913 Dunedin New Zealand E: stephen.duffull@otago.ac.nz P: +64 3 479 5044 F: +64 3 479 7034 Design software: www.winpopt.com