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RE: [NMusers] variation of time values in output data

From: Klaas Prins <klaas.prins_at_qpharmetra.com>
Date: Tue, 21 Apr 2015 10:48:17 +0000

If you subtract (DATE-1) * 24 from TIME in the output file it will match TIME in input file.
NONMEM reads DATE as a DATE data item, that’s why. I suspect you won’t have this if you choose another column name for DATE (e.g. DAY). Note that this may also have an effect on the estimation process and thus your parameter estimates may change as well (for the better).

Best regards,
Klaas


From: owner-nmusers_at_globomaxnm.com [mailto:owner-nmusers_at_globomaxnm.com] On Behalf Of Diane-Charlotte Imbs
Sent: Tuesday, April 21, 2015 11:47 AM
To: Leonid Gibiansky
Cc: nmusers_at_globomaxnm.com
Subject: Re: [NMusers] variation of time values in output data

Thank you, Leonid, for your answer but you can see (below) it’s not a rounding issue ; there are udge variations of time ?!!!

INPUT FILE :

ID DATE TIME DV AMT RATE MDV EVID
3 1 0 0 2000 -2 1 1
3 1 2.6 1060 . . 0 0
3 1 170.1166667 331 . . 0 0
3 2 170.1166667 . 2000 -2 1 1
3 2 172.1166667 1220 . . 0 0
3 2 326.3333333 220 . . 0 0
3 3 326.55 . 2000 -2 1 1
3 3 328.6166667 964 . . 0 0
3 3 504.8333333 1260 . . 0 0

OUTPUT FILE :

ID DATE TIME IPRED CL D1 V1 IWRES
3 1 0 0 1.7711 113.17 35.217 0
3 1 2.6 1223 1.7711 113.17 35.217 -0.13328
3 1 170.12 567.29 1.7711 113.17 35.217 -0.41653
3 2 194.12 169.68 1.7711 112.49 35.217 -1
3 2 196.12 1114 1.7711 112.49 35.217 0.09514
3 2 350.33 1110 1.7711 112.49 35.217 -0.80181
3 3 374.55 328.36 1.7711 140.63 35.217 -1
3 3 376.62 1089.8 1.7711 140.63 35.217 -0.11542
3 3 552.83 1208.1 1.7711 140.63 35.217 0.04297



Loïc FIEVET
Interne IPR en pharmacocinétique

Institut Universitaire du Cancer Toulouse - Oncopole
1 avenue Irène Joliot-Curie
31059 TOULOUSE Cedex 9









2015-04-20 19:21 GMT+02:00 Leonid Gibiansky <lgibiansky_at_quantpharm.com<mailto:lgibiansky_at_quantpharm.com>>:
it could be rounding issue when the precision of the TIME in the data file exceeds the precision of the TIME in the output of the table. You could increase precision of the output using format statement (see manual). Other than that, NONMEM should not change TIME variable.

Leonid

--------------------------------------
Leonid Gibiansky, Ph.D.
President, QuantPharm LLC
web: www.quantpharm.com<http://www.quantpharm.com>
e-mail: LGibiansky at quantpharm.com<http://quantpharm.com>
tel: (301) 767 5566



On 4/20/2015 12:12 PM, Diane-Charlotte Imbs wrote:
Dear nonmem users,

We used the option “-2 RATE” of NONMEM (actual rate of infusion is
unknown): within the control stream:

D1=THETA(1)

Moreover, since several infusions are given to the same patients, we
have added an inter-occasion variability on D1 (see code below)*

We obtained nice fit BUT in the OUTPUT DATA: TIME values corresponding
to blood samples (and DV) are not identical to the actual TIME values of
the INPUT data !?

It seems that NONMEM program adjusts rate values, their interoccasion
variability, and sampling times to have a good fit

*How to fix TIME value corresponding to blood samples ? Indeed, we do
not know the actual infusion rate but we do know the sampling times.*

**

Can anyone tell me if I chose the right model or help me resolving this?

Thanks in advance,

*$PK

OCC1=0

OCC2=0

IF(DATE.EQ.1) OCC1=1

IF(DATE.EQ.2) OCC2=1

D1=THETA(1)*EXP(ETA(3)+ETA(4)*OCC1+ETA(5)*OCC2)

$THETA (0,168,);D1

$OMEGA .1 ; iiv d1

$OMEGA BLOCK(1) .01 ; iov ETA4 OCC1

$OMEGA BLOCK(1) SAME ; iov ETA5 OCC2


*Loïc FIEVET*

*/Interne IPR en pharmacocinétique (1^er semestre)/*

*Institut Universitaire du Cancer Toulouse - Oncopole*

1 avenue Irène Joliot-Curie

31059 TOULOUSE Cedex 9
Received on Tue Apr 21 2015 - 06:48:17 EDT

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