## steady state in WinNonlin (example) [Software]

Dear PKPDPKPD!

» Thanks for your instructions. However, I have two problems:

» 1. The version 5.01 of WinNonLin that I have do not have "Linear" function in the PK/PD/NCA Wizard.

Just looked it up in the release notes, linear models were introducted in v5.1 (23 Oct, 2006). If you have a valid license (which I assume), you may update at no costs.

» 2. The approach I would like to use for the assessment of steady state is repeated measures ANOVA of log concentrations instead of linear regression you are describing, since I am comparing the pre-dose concentrations in several subjects on three consecutive days.

» If I have one dependent variable (concentration) and subject as a random effect (??), and day as a fixed effect (???), how can I use Lin Mix to do the calculations.

OK, ANOVA is not included in WinNonlin; you will have to fight through a Linear Mixed Effects Model (which is always a little bit tricky). One hint: all effects are fixed!

Since I haven't done this myself yet, maybe another member of the forum can fill in the gap?

...or ask Pharsight's support - and be patient!

I know some colleagues are using repeated measures ANOVA; I never could understand why.

The outcome is always a yes/no result.

What if you get a significant result - would you really throw away the entire study?

If you are testing individual subjects, you have the option - providing you have stated such a procedure in the protocol - to exclude only these subjects from the evaluation since they did not reach steady state.

» In the linear regression while assessing the slope, should it be 95% or 90% CI?

95% since p = 1-alpha, where alpha=0.05. This is only a convention.

In BE we are only using a 90% CI, because in patients BA of the test can either be

Therefore the

» Thanks for your instructions. However, I have two problems:

» 1. The version 5.01 of WinNonLin that I have do not have "Linear" function in the PK/PD/NCA Wizard.

Just looked it up in the release notes, linear models were introducted in v5.1 (23 Oct, 2006). If you have a valid license (which I assume), you may update at no costs.

» 2. The approach I would like to use for the assessment of steady state is repeated measures ANOVA of log concentrations instead of linear regression you are describing, since I am comparing the pre-dose concentrations in several subjects on three consecutive days.

» If I have one dependent variable (concentration) and subject as a random effect (??), and day as a fixed effect (???), how can I use Lin Mix to do the calculations.

OK, ANOVA is not included in WinNonlin; you will have to fight through a Linear Mixed Effects Model (which is always a little bit tricky). One hint: all effects are fixed!

Since I haven't done this myself yet, maybe another member of the forum can fill in the gap?

...or ask Pharsight's support - and be patient!

I know some colleagues are using repeated measures ANOVA; I never could understand why.

The outcome is always a yes/no result.

What if you get a significant result - would you really throw away the entire study?

If you are testing individual subjects, you have the option - providing you have stated such a procedure in the protocol - to exclude only these subjects from the evaluation since they did not reach steady state.

» In the linear regression while assessing the slope, should it be 95% or 90% CI?

95% since p = 1-alpha, where alpha=0.05. This is only a convention.

In BE we are only using a 90% CI, because in patients BA of the test can either be

*lower*(5%) or*higher*(5%) then BA of the reference.Therefore the

*individual patient's*risk is kept at 5%.—

Cheers,

Helmut Schütz

The quality of responses received is directly proportional to the quality of the question asked. ☼

Science Quotes

Cheers,

Helmut Schütz

The quality of responses received is directly proportional to the quality of the question asked. ☼

Science Quotes

### Complete thread:

- assessment of steady state in WinNonLin pkpdpkpd 2007-04-04 22:52
- steady state in WinNonlin (example) Helmut 2007-04-05 02:30
- steady state in WinNonlin (example) pkpdpkpd 2007-04-05 16:33
- steady state in WinNonlin (example) Helmut 2007-04-05 17:16
- steady state in WinNonlin (example) pkpdpkpd 2007-04-05 17:39
- steady state in WinNonlin… Helmut 2007-04-05 18:40
- steady state in WinNonlin… pkpdpkpd 2007-04-05 21:37
- Paired Design in WinNonlin Helmut 2007-04-06 00:23

- steady state in WinNonlin… Helmut 2007-04-05 18:40

- steady state in WinNonlin (example) pkpdpkpd 2007-04-05 17:39

- steady state in WinNonlin (example) Helmut 2007-04-05 17:16
- steady state in WinNonlin (example) apapanas 2018-01-03 14:44
- steady state in WinNonlin (example) Helmut 2018-01-04 17:11
- qt in WinNonlin mittyri 2018-01-04 23:13
- ‘Deep’ bug Helmut 2018-01-05 00:37
- Workarounds for v6.3+ Helmut 2018-01-08 00:40
- Workarounds for v6.3+ apapanas 2018-01-10 12:47

- qt in WinNonlin mittyri 2018-01-04 23:13

- steady state in WinNonlin (example) Helmut 2018-01-04 17:11

- steady state in WinNonlin (example) pkpdpkpd 2007-04-05 16:33

- steady state in WinNonlin (example) Helmut 2007-04-05 02:30