Bioequivalence and Bioavailability Forum 09:42 CEST

Main page Policy/Terms of Use Abbreviations Latest Posts

 Log in |  Register |  Search

EquivTest 2.0: defective! [Software]

posted by Helmut Homepage - Vienna, Austria, 2018-05-16 11:47  - Posting: # 18769
Views: 1,043

Hi Irene,

» I conducted a data analysis for imbalance datasets from a journal entitled "Reference Dataset for 2-Treatment, 2-sequence, 2-period bioequivalence studies" (Dataset C) with EquivTest 2.0 and I compared the results with the ones stated in journal. I found that Equivtest 2.0 result (Point of estimate and 90% Confidence Interval) was not identical with EquivTest/PK (the result that stated in the journal). My Equivtest 2.0 result for point of estimates and confidence interval were:
»
» point of estimate (90% CI) : 66.78 (44.94,99.24)
»
» The result according to Journal (EquivTest/PK)
» point of estimate (90% CI) : 58.56 (39.41,87.03)

Congratulations! You discovered yet another defective software. :angry:
The result in EquivTest/PK agrees with ones of other software we have tested (SAS, Phoenix/WinNonlin, R). Screenshot:

[image]


The result you got in EquivTest 2.0 agrees with Kinetica 5.01 – which is wrong.1

Amazingly enough the correct formula taking the number of subjects / sequence (n1, n2) into account is given in the “User Reference Manual”, Chapter 8: Equivalence Testing (p. 166, p. 188 of the PDF) of v2.0 (dated 2001-10-12):

[image]


Did the developers update the manual but not the code

Anyhow, even if you upgrade to EquivTest/PK (of 2006)2 sooner or later you will face other problems. The Welch/Satterthwaite correction for parallel designs with unequal group sizes and/or unequal variances is not supported.3 Furthermore, you will not be able to assess replicate studies intended for reference-scaling according to regulatory requirements (FDA, EMA, WHO, ASEAN States, Australia, Brazil, Egypt, the Russian Federation, the Eurasian Economic Union, New Zealand).

I strongly suggest to get ‘better’ software.


  1. The defect for unbalanced 2×2×2 crossover designs was corrected in Kinetica 5.1 SR1 (2014-12-24). However, the flawed calculation of parallel designs with unequal group sizes was not corrected (see there).
  2. How? On the website of Statistical Solutions Ltd it is not listed any more.
  3. Fuglsang A, Schütz H, Labes D. Reference Datasets for Bioequivalence Trials in a Two-Group Parallel Design. AAPS J. 2015;17(2):400–4. doi:10.1208/s12248-014-9704-6. [image] free view-only version.

Cheers,
Helmut Schütz
[image]

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

Complete thread:

Back to the forum Activity
 Mix view
Bioequivalence and Bioavailability Forum |  Admin contact
18,761 posts in 3,996 threads, 1,264 registered users;
online 21 (1 registered, 20 guests [including 15 identified bots]).

The purpose of models is not to fit the data,
but to sharpen the questions.    Samuel Karlin

The BIOEQUIVALENCE / BIOAVAILABILITY FORUM is hosted by
BEBAC Ing. Helmut Schütz
HTML5 RSS Feed