在藥物的第二、三階段的臨床試驗(yàn)時(shí)，藥物的安全性和有效性是測(cè)驗(yàn)的主要指標(biāo)。Hsu 和Berger在藥物各個(gè)劑量組的方差σ²都相等這一假設(shè)下，提出一種識(shí)別最小有效劑量的逐步置信區(qū)間方法。而方差齊性假設(shè)條件通常是不合理的，本文主要利用 Stein 兩階段抽樣方法，給出方差無(wú)任何限制條件下識(shí)別最小有效劑量（MED）的逐步置信區(qū)間方法。

It is very important to be guaranteed that drug’s safety and efficiency to the mankind in Phase II and III clinical trials. Recently Hsu and Berger (1999) proposed a stepwise confidence interval method in dose-finding of minimum effective dose (MED) for dose-response study under equal variances. This is often in doubt. A new way to find MED was proposed by employing the Stein’s two-stage sampling method, the stepwise confidence procedure was proposed without any condition imposed on the variance. And the error rate is properly controlled.