RE: Bootstrap resampling!
From: "Banken, Ludger {PDBS~Basel}" <LUDGER.BANKEN@Roche.COM>
Subject: RE: Bootstrap resampling!
Date: Wed, 28 Mar 2001 11:40:30 +0200
I do not fully agree with Paul and Nick that the sample unit for bootstrapping should be the subject. In population PK/PD data there are two sources of random variation, inter- and intra-subject variation. A good approach to handle the inter-subject variability is to resample among the subjects. But I believe that additional resampling is necessary to take the intra-subject variability into account, resulting in a two-stage bootstrapping. Without it the intra-subject variability is treated as nonexistence. I must admit that I don't know about a reasonable method without assumptions. But it might even be better to use a non-optimal method than none at all. But the proposal needs to be investigated, by simulations or conceptual work before it should be used in practice.
Does anybody know that such a two-stage bootstrap method is used somewhere or that it has been discussed in the literature?
Best regards,
Ludger
Ludger Banken
PDBS, 74/3.OG W
Hoffmann-La Roche, Ltd.
CH-4070 Basel, Switzerland
Phone: ++41 61 68 87363; Fax: ++41 61 68 814525;
E-mail: Ludger.Banken@roche.com