Bioequivalence and Bioavailability Forum

Dear Krishnamurthy!

❝ Example 1: In case of a 4 period replicate design study, if the subject has completed only 2 periods (one test and one reference) could this subject be considered as having completed the study?

No, since the design called for 4 periods, the subject did not complete the entire study...

❝ In continuation of the above, if the protocol indicates that all subjects who have completed the study will be included for PK and Stats, should the above subject be included or excluded from PK and Stats?

What was laid down in the protocol?
If completion meant 4 periods, the subject should have been excluded from the BE assessment - but PK data of the 2 completed periods must still be presented and accounted for (why did he drop out: personal reasons, AEs, were the concentrations higher than 'normal', etc.)
If completion meant at least 2 periods - where like in your example test and reference are covered - it's possible to recover some information and include it in the BE assement by means of linear mixed-effects modeling (LMEM). See this post.

Remark: whereas the former is the 'conventional' approach, the latter is also possible, but the gain in statistical power (i.e., the width of the confidence interval) generally is minuscule.