PRED values
From: bvatul@ufl.edu
Subject: PRED values
Date: Thu, 17 May 2001 23:54:43 -0400
Hello All
Could somebody advise me on this?
I am analyzing the data of a drug and its metabolite using ADVAN6 and FO method in healthy (rich) and patients (sparse) data sets. I am surprised at one result in the output, ie.,PRED. Say, at time 4h the PRED values at a dose group should be same. This I am observing in rich data set. But when I am analyzing the sparse data set, say at 4h, I am not observing exactly the same PRED values in the output. For some time points the PRED values are same but for they are different slightly for some points. I have written the values below. What could be the possible reason? I checked my data set and it is fine. Is there any statistical reason (distribution patterns) behind this or am I wrong somewhere? I would be happy if someone could rectify me in this.
Rich data (normal subjects)
Dose: 150 mg
TIME DV PRED
4 318 322.33
4 319 322.33
4 390 322.33
4 298 322.33
4 393 322.33
4 391 322.33
Sparse data Dose 150 mg
TIME DV PRED
4 288 143.20
4 376 143.20
4 276 143.15
4 191 143.15
4 182 143.15
4 262 143.42
4 99.7 143.15
4 130 143.15
4 144 143.68
4 215 143.15
4 207 143.15
4 369 143.15
4 153 143.15
4 260 143.15
Sparse data
TIME DV PRED
3.8 101 148.68
3.8 137 148.68
3.8 346 148.68
Thanks a lot
Atul