ABSTRACT
Because of differences in many intrinsic and extrinsic factors among regions, it is naturally possible that treatment effects are different across regions. Therefore, besides the estimate of the overall treatment effect for the whole multiregional clinical trial (MRCT), there is a need to quantify treatment effects of individual regions so that health authorities can determine the utility of the drug for their patients. In this section, we first discuss various estimates for quantifying regional treatment effects, and then apply these regional estimates to assess consistency of treatment effects. The corresponding required sample sizes will also be discussed. The notation defined in Chapter 7 will be used in this chapter.
