Posthoc comparisons [Software]

posted by Helmut Homepage – Vienna, Austria, 2010-03-25 19:34 (5926 d 12:51 ago) – Posting: # 4973
Views: 4,841

Dear key,

nice that you accost me personally, but searching the forum you would have noticed that I don't have the slightest idea about
[image]

❝ Have a working SAS model for a replicate design, 2 treatments, 4 periods

❝ (each treatment is delivered twice).


Define 'working model'. For ABE, IBE/PBE?

❝ Now need to do followup analysis on the 4 individual treatment

❝ comparisons

❝ A1vA2

❝ B1vB2

❝ A1vB1

❝ A2vB2


❝ and am having a little bother programming the model.


I guess that your indices denote the order of administrations regardless the period? Let's have a look at FDA's baby:
     P1 P2 P3 P4
S1:  T  R  R  T
S2:  R  T  T  R

So are you thinking about something like:
     P1 P2 P3 P4
S1:  A1 B1 B2 A2
S2:  B1 A1 A2 B2

I don't think that your between occasion (within treatment) comparisons make sense - and I would say they are confounded with the period effect as well. Overall I'm not even sure whether I understand the rationale behind your four questions (especially the last two). In other words - what do you want to know?

❝ Can this even be done using proc mixed?


I don't think so; I would say you are asking the wrong questions. But I'm only a statistical amateur and not gifted with [image]...

Dif-tor heh smusma 🖖🏼 Довге життя Україна! [image]
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