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RE: dataset codification

From: Xia Li <lix4>
Date: Wed, 24 Sep 2008 16:51:13 -0400

Mark,

When you use EVID =3, you reset the system. Time should be set to =
whatever time appears at the new event.(0 in your case). This option is =
usually used in inter occasion study within an individual record.

If you use EVID=4, you reset the system and introduce an new dose =
record. It is identical to EVID=3 plus EVID=1.

ID TIME EVID...
1 0 1
1 1 0
... ... ...
1 0 4



is the same as

 

ID TIME EVID...
1 0 1
1 1 0
... ... ...
1 0 3
1 0 1



Xia Li

 

 

 

Xia Li

Department of Mathematical Science

University of Cincinnati

 

 

From: owner-nmusers
On Behalf Of Mark Gutierrez
Sent: 2008年9月24日 14:11
To: nmusers
Subject: Re: [NMusers] dataset codification

 

Dear all,

 

First of all, thank you for your prompt reply.

 

 

Following with my doubts. In my case where the time between first and =
second dose is two months, I understand that I could substitute in Time =
column the real time (24hours * 2 months) by 0 when the second dose is =
administered. Is that correct? Or as you mentioned I should include the =
real time

 

ID TIME EVID...
1 0 1
1 1 0
... ... ...
1 0 4
... ... ...

On the other hand,
In the help guide, when the interoccasion variability example is =
described, the dataset is arranged with EVID = 3 including an extra =
line previous to the second dose (second occasion) and restarting TIME =
with 0

 

ID TIME EVID...
1 0 1
1 1 0
... ... ...
1 0 3
1 0 1

1 1 0
... ... ...

This could be another solution to my problem. Isn’t it?

 

Thank you again.

Mark

 

 

 

 

 

 

----- Mensaje original ----
De: Sébastien Bihorel <sbihorel
Para: "Willavize, Susan A" <susan.a.willavize
CC: Mark Gutierrez <markgutierrez977
Enviado: miércoles, 24 de septiembre, 2008 19:03:43
Asunto: Re: [NMusers] dataset codification

You are right Susan: the Time values have to increase within a subject. =
Using EVID=4 allows you to use a more convenient time scale
ex:

ID TIME EVID...
1 0 1
1 1 0
... ... ...
1 24 4
... ... ...

instead of

ID TIME EVID...
1 0 1
1 1 0
... ... ...
1 26546 1
... ... ...

Assuming you don't have any measurement after 24h during the first =
period of your study.

Willavize, Susan A a écrit :

I have seen EVID=4 used, but don’t remember the details. How =
does the time variable look? I always convert Date and time to a time =
counting variable that starts at 0 time (time of first dose) and always =
increases within each subject. I recall that when EVID= 4 is used, =
the time variable does NOT need to restart with the second dose. Do I =
remember correctly?

 

 

Note I do not include DATE and clock TIME in my NONMEM input, since I =
have seen NONMEM do nefarious things with these.

 

Susan

  _____

From: owner-nmusers
On Behalf Of Sébastien Bihorel
Sent: Wednesday, September 24, 2008 5:52 AM
To: Mark Gutierrez
Cc: nmusers
Subject: Re: [NMusers] dataset codification

 

Dear Mark,

You may want to read about "EVID" in the html help. EVID = 4 is what =
you mean. It is a dosing event but implies that the system is reset =
before the dose is introduced into the system.

Sebastien

Mark Gutierrez a écrit :

Dear all,

 

I am modeling some PK data from one rabbit. And I have some doubts how =
to codify the dataset. The rabbit received different single doses of a =
drug at different times.

 

E.g,

First of May it received a 100 mg dose i.v. ,

Then, 2 months latter (enough washout period), the first of July, it =
received and oral dose of 100mg..

Finally, after other two months the rabbit received the last oral dose =
200mg.

 

I could codify in the TIME column the real times, including the jumps of =
two months, but I think that there is an option in Nonmem to =
“restart” the dose through the dataset.

 

Could somebody clarify me this point? and perhaps include a simple =
example of dataset.

 

Thank you in advance

Mark

 

 


Received on Wed Sep 24 2008 - 16:51:13 EDT

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