Seminars

A note on confidence bounds after step-down tests

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Yi-Hsuan Tu

2010-11-05
12:45:00 - 14:45:00

405 , Mathematics Research Center Building (ori. New Math. Bldg.)

We are concerned with the problem of estimating the treatment effect at the effective doses in a dose-finding study. Under monotone dose-response, the effective doses can be identified through the estimation of the minimum effective dose, for which there is an extensive set of statistical tools. In particular, if a step-down procedure is used to estimate the minimum effective dose, Hsu and Berger (1999, Journal of the American Statistical Association) show that the confidence bound for the treatment effect can be constructed without the need to adjust for multiplicity. Their method, called the dose-response method, is simple to use, but does not account for the magnitude of the observed treatment effect. As a result, the dose-response method will estimate the treatment effect at effective doses with confidence bounds invariably identical to the hypothesized value. In this paper, we propose a two-step procedure to construct confidence bounds at the identified effective doses.