From: "Tsai, Max" max.tsai@spcorp.com
Subject: [NMusers] Random sampling times
Date: Mon, March 14, 2005 8:30 am
Hello all. I am trying to design a sparse sampling scheme by
simulating random sampling times, which would subsequently be used
to generate concentration data. This data would then be fitted
to a previously developed POPPK model and the PK parameters
would be compared to those modeled from the full time series.
I would like to implement a control stream that would simulate
a time series with the capability of generating random deviations
from the nominal time within certain time intervals (e.g. 1-4 or
8-12 hr) and possible missed sampling times as shown below. How
would this be implemented using either CALL RANDOM statement or
verbatim code? I can generate a time series easily outside
NONMEM (e.g. in SAS), but I would like to use NONMEM to produce
multiple replicate sets of random sampling times and utilize the
$SUPER statement to automate the process of simulation and
estimation within NONMEM, similar to the proposed control
stream submitted by Dr. Banken several years ago.
( http://www.cognigencorp.com/nonmem/nm/99feb152000.html) Thanks.
ID NOMTIME REALTIME DV
1 0 0.02 .
1 4 2.6 .
1 8 . . <- ultimately, this line will need to be removed prior to simulating concentrations
1 24 23.8 .
2 0 0.53 .
2 4 1.2 .
2 8 8.5 .
2 24 . . <- ultimately, this line will need to be removed prior to simulating concentrations
etc.
Max Tsai, Ph.D.
Senior Scientist (DM/PK)
Schering-Plough Corporation
2015 Galloping Hill Road
K-15-2-2650
Kenilworth, NJ 07033-0530
(: (908) 740-3911
: (908) 740-2916
*: max.tsai@spcorp.com
Random sampling times
From: "Bachman, William (MYD)" bachmanw@iconus.com
Subject: RE: [NMusers] Random sampling times -> He Sun
Date: Mon, March 14, 2005 8:55 am
Dr. He Sun at the FDA did some work with simulation of sampling times several
years ago. You might try contacting him or looking for his references.
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