Re: Standard error of 'secondary' parameters

Date: Sat, 13 Nov 1999 08:23:18 +1300 From: Nick Holford <n.holford@auckland.ac.nz> Subject: Re: Standard error of 'secondary' parameters Thanks. Thats pretty obvious now you point it out :-) But to come back to the original thread I wonder why anyone would bother trying to estimating SEs on secondary parameters using the usual NONMEM aysmptotic method. These estimates are barely worth the electrons used to display them on the screen except perhaps as some kind of rough diagnostic. If you really want to know about the confidence of a 'secondary' parameter estimate then I would suggest either the log likelihood profile method (but that requires re-parameterization with the possible change in the model that you allude to above) or bootstrap (but that needs at least 1000 NONMEM runs to get reasonable values for a confidence interval). -- Nick Holford, Dept Pharmacology & Clinical Pharmacology University of Auckland, Private Bag 92019, Auckland, New Zealand email:n.holford@auckland.ac.nz tel:+64(9)373-7599x6730 fax:373-7556 http://www.phm.auckland.ac.nz/Staff/NHolford/nholford.html