Group effects FDA/EMA [Two-Stage / GS Designs]

posted by mittyri – Russia, 2014-08-21 15:34 (2174 d 13:07 ago) – Posting: # 13416
Views: 33,216

Dear Helmut,

» Group = not a reasonable effect?

As I understand correct, no one can answer on this question...
I've read some topics about group effect in the statistical model, by the way I still have some questions
1. Is it obligatory EMA's requirement to use Group effect in the model in all cases when there is more than one group? Any experience of LoDs due to absence of Group effect in the statistical model?

2. What kind of statistical model is preffered for Europe submission?
According to the Detlew's post
» In context of a 2-Stage design, also a 2-group design with groups here called stage, the mighty oracle prohibit us the Group-by-Treatment Interaction! From the EMA Q&A Rev.7 :
» "Conclusion ... A term for a formulation*stage interaction should not be fitted."
ElMaestro wrotes that
» Although I think the formulation x group interaction would steal a df and would be tested against the model residual (within). You are right that any step towards increasing the model residual translates into producer's risk.

Did you ever use the model without group × treatment?
Something like that:
Fixed: sequence, period, treatment, group, subject(sequence)

3. Did you ever got the requests from EMA experts about calculating the CI into one of the groups as for FDA submision?

Sorry for probable repeating some questions

Edit: I’m off for a three weeks vacation. I’m sure others will have a lot to say in the meantime. ;-) [Helmut]

Kind regards,

Complete thread:

 Admin contact
20,964 posts in 4,373 threads, 1,459 registered users;
online 16 (0 registered, 16 guests [including 14 identified bots]).
Forum time: Tuesday 04:42 CEST (Europe/Vienna)

My doctor gave me six months to live,
but when I couldn’t pay the bill
he gave me six months more.    Walter Matthau

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