BE study stratified per body weight group [General Statistics]
I am facing an interesting BE study and would be happy to get the forum members thoughts on the analysis strategy
Background: one reference (R) and two test items (T1, T2) with different doses per body weight stratum
Body weight stratum 1: x mg for T1, T2 and R for subjects < z kg
Body weight stratum 2: y mg for T1, T2 and R for subjects > z kg
Study design: Williams’ design (3-treatment, 3-period, 6-sequence) with stratified randomization according to body weight stratum (<z kg and > z kg) to ensure balance regarding this strata.
1) Can the BE assessment be based on all data combined or does this require a separate analysis per body weight stratum
2) If a combined assessment is the way to go how should the model look like
a) Ignoring body weight strata and use classical model (FDA): fixed effects for period, sequence, treatment and random effect for subject nested in sequence.
b) Including body weight strata as mentioned in ICH E9 (i.e. factors on which randomization has been stratified should be accounted for later in the analysis): fixed effects for period, sequence, treatment, body weight strata and random effect for subject nested in sequence.
Best regards and looking forward to an interesting discussion
Edit: Category changed; see also this post #1. [Helmut]