Weights for AUC in a logistics regression

From farkad.ezzet@chbs.mhs.ciba.com Thu Oct 17 05:15:47 1996 Subject: Weights for AUC in a logistics regression Dear NONMEM users, In a recent population analysis, my data involved about 200 patients. Of which 50 had extensive sampling (16 samples) and the remaining 150 had about 4 samples each. I obtained a good fit for the data with NONMEM. Upon examination of the eta's (subject deviations form the population estimates), the variability appears similar in the extensively sampled and in the sparsely sampled patient (which is a good thing). My question is the following: Take clearance for example, defined as CL(i) = CL * exp[eta(i)], where i refers to the ith subject. Should CL(i) be more precisely estimated if the ith subject is extensively sampled compared to when sparsely sampled (a consequence of the weighted LS method implemented in NONMEM) ? If so, how more precise ? Is there an obvious measure out of NONMEM to use. I am interested in using AUC(i)=dose/CL(i) as a covariate in a logistic regression whereby my response variable is success/failure to treatment. Do you advise to use a weight for AUC such that it reflects the precision with which AUC was calculated ? I look forward to hearing you reply. Farkad EZZEZ