Science vs. regulations [Regulatives / Guidelines]

posted by Helmut Homepage – Vienna, Austria, 2020-05-07 23:54 (175 d 05:44 ago) – Posting: # 21405
Views: 7,399

Hi Achievwin,

» Then a priori in the protocol SAP include limitations on reporting AUCinf and %Extrp.
» 1. R2>0.800

Why this – arbitrary – number? Given, I have seen it in lots of SAPs.
\(\small{R^2}\) (strongly!) depends on the number of time points \(n\) (see this rather old thread). \(\small{R_{\textrm{adj}}^{2}}\) is better though still not independent from \(n\) (that’s a misconception sold by software vendors).
If clearance is variable and/or the analytical variability is high, a low correlation may be perfectly fine, whereas in the opposite case even 0.9 may indicate a poor fit. Unless you have data of a previous study with the same analytical method, IMHO, a pre-specified cut-off does not make sense.
Furthermore, never trust in results of a silicon-based life-form. Visual inspection of the fit is mandatory.

PS: 0.8 with three significant digits: 0.8005 is OK and 0.8004 not. Really?

Dif-tor heh smusma 🖖
Helmut Schütz
[image]

The quality of responses received is directly proportional to the quality of the question asked. 🚮
Science Quotes

Complete thread:

Activity
 Admin contact
21,179 posts in 4,414 threads, 1,474 registered users;
online 6 (0 registered, 6 guests [including 4 identified bots]).
Forum time: Friday 04:39 CET (Europe/Vienna)

The idea is to try and give all the information to help others
to judge the value of your contribution;
not just the information that leads to judgment
in one particular direction or another.    Richard Feynman

The Bioequivalence and Bioavailability Forum is hosted by
BEBAC Ing. Helmut Schütz
HTML5