Bioequivalence and Bioavailability Forum

Dear Yung-jin!

❝ ❝ Which dataset are you using (I want to recalculate your results)?

❝ The data we used to test "outlier function" was the one built-in in bear. So it should be easy to find out from previous version of bear (e.g., v2.0.1..)

OK, checked lnCmax and could reproduce your model estimates and residuals in an old program I once wrote in STATISTICA.
Running Shapiro-Wilk in R gives
        Shapiro-Wilk normality test

data:  intra
W = 0.9333, p-value = 0.3389
in agreement with NCSS (W 0.9332635, p 0.338826), but different from your results (0.93758 0.3882)?!

BTW for log-transformed C_max data the output reads:
Intra_subj. CV=100*sqrt(MSResidual)= 12.60176 %
Inter_subj. CV=100*sqrt((MSSubject(seq)-MSResidual)/2)= 7.554316 %
Acc. to D Hauschke et al.; Int J Clin Pharmacol Ther 32/7, 376-378 (1999) in the multiplicative model it should be
Intra_subj. CV=100*sqrt(exp(MSResidual)-1)= 12.65195 %
Inter_subj. CV=100*sqrt((exp((MSSubject(seq)-MSResidual)/2)-1))= 5.19586 %

❝ ❝ Another suggestion would be a plot of ln(predicted) vs. studentized residuals. [...]

❝ What a fantastic idea!

Oh, this is not my invention; I'm just a dwarf standing on the shoulders of giants.

❝ In your slides, you even provide much more information about outlier detection...

Do I?

❝ ...than the textbook of Chow SH, Liu JP. "Design and Analysis of Bioavailability and Bioequivalence Studies", 3rd ed. (Chapman & Hall/Crc Biostatistics Series).

Hhm, I have it on my desk just for a couple of days now. Disappointing that some typos are still uncorrected (Table 8.2.1, model value of subject 18 which was correct with 4.581 in ed. 1 is given with 4.851 in eds. 2/3). Another great method to check influential observations is Cook's distance, whereas personally I find the Tukey sum–difference plot and the Equal variance plot less convincing (especially in detecting outliers). See S-Plus-code in Chaper 7 of Millard and Krause (2001) by B Pikounis, TE Bradstreet and SP Millard here.

❝ [...] the great presentation you just made in India. Lucky audiences in that meeting.

Yeah, it was great fun!

❝ Just no budget to go this time.

Don't bother - it was a basic workshop (mainly); you would have been bored.

❝ We want to thank you again for your valuable comments.

Welcome & thanks for your work and keeping the spirit of

high.