EquivTest 2.0: defective! [Software]
❝ 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.
The result in EquivTest/PK agrees with ones of other software we have tested (SAS, Phoenix/WinNonlin, R). Screenshot:
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):
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.
- 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).
- How? On the website of Statistical Solutions Ltd it is not listed any more.
- 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. free view-only version.
Dif-tor heh smusma 🖖🏼 Довге життя Україна!
The quality of responses received is directly proportional to the quality of the question asked. 🚮
- Imbalance dataset analysis with Equivtest 2.0 Irene_I 2018-05-16 09:02 [Software]