Banana splits [Two-Stage / GS Designs]

posted by Helmut Homepage – Vienna, Austria, 2015-06-02 02:48 (3222 d 14:31 ago) – Posting: # 14889
Views: 18,497

Hi Dan,

plots from my garbage-collection about asymmetric splits of αadj. GMR 0.95, target power 80%. Stage 1 sample sizes 12–72 and CVs 10–80%; both assessed with a step size of two. 106 sim’s for the Type I Error and 105 for power.

Haybittle/Peto: misused 0.001/0.049 (CIs 99.80/90.20%)
TIEmax 0.0585 (at n1 12, CV 24%)


[image]

Haybittle/Peto: adjusted 0.001/0.0413 (CIs 99.80/91.74%)
TIEmax 0.0499 (at n1 12, CV 22%)


[image]

O’Brien/Fleming: misused 0.005/0.048 (CIs 99.00/90.40%)
TIEmax 0.0570 (at n1 12, CV 24%)


[image]

O’Brien/Fleming: adjusted 0.005/0.0416 (CIs 99.00/91.68%)
TIEmax 0.0501 (at n1 12, CV 24%)


[image]

Zheng et al.: 0.01/0.04 (CIs 98.00/92.00%)
TIEmax 0.0488 (at n1 12, CV 24%)


[image]

Zheng et al.: adjusted 0.01/0.0412 (CIs 98.00/91.76%)
TIEmax 0.0498 (at n1 12, CV 26%)


[image]

With Haybittle/Peto the TIE may hit all over the place; O’Brien/Fleming per­forms slightly better. Zheng et al. is overly con­ser­va­tive.
Note that these adjustments are applicable to a GMR of 0.95 and target power of 80% only. More de­viation of the GMR from unity and/or higher target power generally requires more adjustment (i.e., lower α2 ⇒ wider CI). I know some people using HP for a GMR of 0.90. :no:

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

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

Complete thread:

UA Flag
Activity
 Admin contact
22,957 posts in 4,819 threads, 1,638 registered users;
79 visitors (0 registered, 79 guests [including 12 identified bots]).
Forum time: 16:19 CET (Europe/Vienna)

Nothing shows a lack of mathematical education more
than an overly precise calculation.    Carl Friedrich Gauß

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