Posthocs

From: Baerbel Wittke 41 61 68 85067 <BAERBEL.WITTKE@roche.com> Subject: Posthocs Date: 16 Jul 1997 12:44:20 -0400 Hello, I have a data set from a phase III study containing steady state plasma concentrations of a compound after an iv infusion for about 50 % of the patients. Dosing and covariable information is available for all patients. I could obtain good posthoc estimates for drug clearance for all patients with plasma levels. My goal is to estimate the steady state plasma levels of the remaining patients (without plasma concentration measurements). When I repeated the posthoc analysis with the complete data set (DV = 0 for the patients without measurements), the posthoc estimates of CL were much too high for these patients. I got reasonable results for the posthocs when I used the predicted plasma levels (based on TVCL) instead of DV = 0 in the data set, but I don't know whether this is the correct way to obtain posthoc estimates for patients without concentration measurements. Has anybody experience with this ?? Thanks, Baerbel Wittke (e-mail: baerbel.wittke@roche.com)