known.designs() [General Sta­tis­tics]

posted by Helmut Homepage – Vienna, Austria, 2018-03-09 15:42 (1324 d 13:18 ago) – Posting: # 18513
Views: 4,305

Hi Louis,

» I thought about the 'paired' design as I looked into known designs(), but I was not sure.

You were guessing right.

» […] in several instances it happens that in period 1 a subject receives what is called the 'probe' while in period 2 it receives the "probe+investigational drug".

Designed without consulting a statistician? Lacking period effects is a strong assumption.
The only designs where a paired design is common is assessing linear PK of a new drug. Such a study starts with a single dose followed by saturation and another profile in (pseudo) steady state. Then we compare AUC0–τ (MD) with AUC0–∞ (SD). Performing such a study as a crossover would be a logistic nightmare. Never ever have seen one.

» I'm trying to find the CV intra associated with a particular "probe" based on DDI study in a published paper (no CV intra, just PE, CI, and N), as I need to use it in the sample size determination (precision only, no power) for a new DDI. Would 'paired' cover this situation?

Yes.

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
21,753 posts in 4,548 threads, 1,544 registered users;
online 2 (0 registered, 2 guests [including 2 identified bots]).
Forum time: Sunday 06:00 CEST (Europe/Vienna)

They were “so intent of making everything numerical”
that they frequently missed seeing
what was there to be seen.    Barbara McClintock

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