Dunnett not for continuous scales? Really? [General Sta­tis­tics]

posted by d_labes  – Berlin, Germany, 2011-11-01 12:11 (4617 d 02:23 ago) – Posting: # 7574
Views: 7,239

Dear Helmut!

❝ ... Since in dose-proportionality (aside from setting up a power model) we often compare dose-adjusted responses to one dose-level (and do not perform all pairwise tests) a variant of Dunnett’s test might be suitable. Unfortunately Dunnett is only applicable for nominal scales, not for continuous ones (doses).

(emphasis by me)

Where does this opinion come from :confused:. AFAIK is Dunnett's test a post-hoc test within the ANOVA framework to compare many means to one control. ANOVA always deals with measurements on continuous (metric) scales. Or do I miss somefink here?

Moreover Hauschke, Steinijans and Pigeot [1] explicitly recommend Dunnett's test for evaluation of studies with more than one Test formulations versus one reference. See Chapter 7.

For dose linearity studies (comparing more then 2 dose adjusted PK characteristics) they derive from the intersection-union principle "... Hence for a joint decision rule where all requirements must be fulfilled, no adjustment of the comparison wise type I error is needed ...". See page 170 of the reference. The argumentation given is plausible for me also as an amateur in statistics I'm not able to prove it.

BTW: Where does the 2-stage design come into play for dose-proportionality studies?

[1] Hauschke, Steinijans and Pigeot
Bioequivalence Studies in Drug Development
Wiley, Chichester 2007



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