Bioequivalence and Bioavailability Forum

Period effects and sequences unrelated [RSABE / ABEL]

posted by d_labes  – Berlin, Germany, 2013-09-23 10:44 (4251 d 08:10 ago) – Posting: # 11541
Views: 8,516

Dear RK,

❝ On reviewing the data of four period two sequence (ABAB and BABA) fully replicated study retrospectively, there is a statistically significant period effect reported for Cmax. So would like to know whether we can use four period four sequence fully replicated study to nullify this period effect ...

If there is a period effect in a crossover study (replicate or not) it means that the subjects behave different in the study periods, irrespective of their treatment in that periods. That implies in turn irrespective of their sequence of treatments.

Thus I can't imagine any reason why such an effect should vanish by using different (or more) sequences.

❝ ... this period effect which is described in the FDA guideline (Appendix B- Reasons Unrelated to Carryover Effects).

Can you elaborate where you found hints about significant period effects in 'Appendix B' ?

Complete thread:

• fully replicate design with six sequences RK 2013-09-14 12:17 
  • Objective? Helmut 2013-09-15 13:47
    • Objective? jag009 2013-09-16 17:24
    • Objective? RK 2013-09-17 13:35
      • Objective? (again) Helmut 2013-09-17 13:51
        • Question: jag009 2013-09-17 15:49
          • Imbalanced/incomplete sequences Helmut 2013-09-18 17:32
        • fully replicate design with four sequence RK 2013-09-20 13:56
          • Period effects and sequences unrelatedd_labes 2013-09-23 08:44
            • Period effects and sequences unrelated RK 2013-09-24 13:16