Accepted time deviations in Ambulatory PK intervals [Regulatives / Guidelines]
Hi ElMaestro and Researcher101,
Agree. The later in the profile, the less critical deviations are.
See this post and followings. I don’t comprehend why too early sampling should be performed. PK calculations (regardless whether by NCA or by modeling) should always be performed based on the actual time points – otherwise the estimates will be biased.
Extremely nasty in modeling. Both OLS and maximum likelihood approaches require that the independent variable is free of any error. It’s a misconception that errors in the independent variable only increase the residual error. If one wants to deal with that, it get’s really, really tricky (orthogonal regression, where the selection of appropriate weights is black magic).
❝ As I see it, one can make a case for saying that the way to deal with time point deviations should be API-specific as well as time-specific.
Agree. The later in the profile, the less critical deviations are.
❝ Some CROs define a window in terms of time (for each time point)…
See this post and followings. I don’t comprehend why too early sampling should be performed. PK calculations (regardless whether by NCA or by modeling) should always be performed based on the actual time points – otherwise the estimates will be biased.
Extremely nasty in modeling. Both OLS and maximum likelihood approaches require that the independent variable is free of any error. It’s a misconception that errors in the independent variable only increase the residual error. If one wants to deal with that, it get’s really, really tricky (orthogonal regression, where the selection of appropriate weights is black magic).
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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:
- Accepted time deviations in Ambulatory PK intervals Researcher101 2020-11-20 17:59 [Regulatives / Guidelines]
- Accepted time deviations in Ambulatory PK intervals ElMaestro 2020-11-21 10:08
- Accepted time deviations in Ambulatory PK intervals Researcher101 2020-11-22 11:52
- Accepted time deviations in Ambulatory PK intervalsHelmut 2020-11-23 11:49
- Accepted time deviations in Ambulatory PK intervals ElMaestro 2020-11-21 10:08