Origin of SAS code? [Software]
Hi Mahmoud,
where does this code come from? It’s not the standard one recommended by the FDA here and there.
I would suggest to use
Acc. to the FDA’s guidance, Appendix E:
Of course.
If this is a full replicate design, I would follow the FDA’s recommendation and use
However, in the stupid partial replicate designs (TRR|RTR|RRT or TRR|RTR) the optimizer may fail to converge since the model is over-specified (T not repeated). Then you’ve performed a study and don’t get a result cause SAS shows you the finger.* I suggest to specify
❝ in the following SAS code
where does this code come from? It’s not the standard one recommended by the FDA here and there.
❝ model AUCT=sequence period treat/DDFM=kr;
I would suggest to use
DDFM=SATTER
(as the FDA recommends). The default of DDFM=KR
uses the observed information matrix (SCORING=0
) as does jmp. You may run into troubles if your study is re-evaluated in other software which uses the expected information matrix (e.g., Stata, R-package replicateBE
). In SAS you can get the expected information matrix by setting SCORING=1
.❝ random treat/type=CSH subject=subject G;
❝
❝ In the Random statement TYPE=CSH
could possibly be replaced by TYPE=FA(1)
Acc. to the FDA’s guidance, Appendix E:
In the Random statement, TYPE=FA0(2)
could possibly be replaced by TYPE=CSH
.
❝ FA(1)
is not the same as FA0(2)
Of course.
FA(q
) = factor analytic and FA0(q)
= no diagonal factor analytic.If this is a full replicate design, I would follow the FDA’s recommendation and use
FA0(2)
.However, in the stupid partial replicate designs (TRR|RTR|RRT or TRR|RTR) the optimizer may fail to converge since the model is over-specified (T not repeated). Then you’ve performed a study and don’t get a result cause SAS shows you the finger.* I suggest to specify
FA0(1)
instead. State that already in the SAP.- If you are lucky SAS throws only a warning.
Convergence criteria met but final hessian is not positive definite.
But if Murphy’s law hits:
WARNING: Did not converge.
WARNING: Output 'Estimates' was not created.
—
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Helmut Schütz
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Science Quotes
Dif-tor heh smusma 🖖🏼 Довге життя Україна!
![[image]](https://static.bebac.at/pics/Blue_and_yellow_ribbon_UA.png)
Helmut Schütz
![[image]](https://static.bebac.at/img/CC by.png)
The quality of responses received is directly proportional to the quality of the question asked. 🚮
Science Quotes
Complete thread:
- SAS code for ABE Mahmoud 2020-07-03 14:09 [Software]
- Origin of SAS code?Helmut 2020-07-03 14:46
- SAS code for ABE Mahmoud 2020-07-03 16:49
- SAS code for ABE jishnu 2022-08-06 18:54
- SAS code for ABE Helmut 2022-08-06 20:48
- Origin of SAS code?Helmut 2020-07-03 14:46