[NMusers] lab values

Dear NMUSERS,#



I would like to ask for some opinions regarding the handling of missing l=
ab values in a NONMEM Dataset;



Our normal procedure:

Parameter values will be carried backward to the first visit if the first=
 visit value is missing, it will be carry forward to the last visit if no=
 value is available at the last visit and will be set at the median value=
 of two adjacent visits in other cases.



Now we have a phase III study (multiple doses), one safety lab at day -1 =
and one safety lab at final examination only, no lab in between (>6 month=
)



Two main strategies are possible



1.) Different from our standard procedure:

Carry the lab value at final examination backward to day -1.



2.) According to our standard: Use the median (or perhaps a regression =
between the first and final examination)

:

My assumptions:

The first strategy might be useful to reflect the influence of the drug o=
n lab values and will reflect the steady state situation.



The second strategy might be better to characterize the influence of the =
lab values on the PK of the drug, e.g if a disease worsens during the stu=
dy.



As our main focus will be the last one, I would use the standard approach=
.



I know that this is quite basic, however as this was discussed during a m=
eeting I would appreciate to have your opinion.



Many thanks in advance



Dirk


Dirk Garmann, PhD
Clinical Scientific Expert /Pharmacokineticist
Merz Pharmaceuticals
Eckenheimer Landstrasse 100
60318 Frankfurt
Phone +49 (69) 1503 720





Merz Pharmaceuticals GmbH, Frankfurt am Main
Amtsgericht Frankfurt am Main, HRB 53808
Geschäftsführung: Dr. Martin Zügel (Vors.), Dr. Alexander Gebauer,
Dr. Karsten Schlemm, Dr. Eugen Wilbert



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Received on Wed Jan 13 2010 - 07:41:00 EST