known.designs() [General Sta­tis­tics]

posted by Helmut Homepage – Vienna, Austria, 2018-03-09 16:42 (1848 d 13:42 ago) – Posting: # 18513
Views: 4,605

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?


Dif-tor heh smusma 🖖🏼 Довге життя Україна! [image]
Helmut Schütz

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

Complete thread:

UA Flag
 Admin contact
22,559 posts in 4,725 threads, 1,607 registered users;
19 visitors (0 registered, 19 guests [including 6 identified bots]).
Forum time: 07:24 CEST (Europe/Vienna)

The penalty for scientific irrelevance is, of course,
that the statistician’s work is ignored by the scientific community.    George E.P. Box

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