Confidence intervals associated with tests for bioequivalence

Previously, the connection between bioequivalence tests and their associated confidence intervals was not well understood. In fact, the α-level two one-sided tests approach was thought to be associated with a 1−2α confidence interval. In this paper, we build up connections which allow us to construct 1−α confidence intervals from α-level tests and vice versa. When applied to the α-level two one-sided tests, the resultant 1−-α confidence intervals are properly contained in Westlake's 1−-α symmetric interval (1976). Our approach is readily generalized to different settings, including the nonparametric setting, the ratio parameter setting, and the repeated confidence interval setting.