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arXiv · 1702.00978

Assurance for clinical trial design with normally distributed outcomes: eliciting uncertainty about variances

Ziyad A. Alhussain·Jeremy E. Oakley
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Abstract

The assurance method is growing in popularity in clinical trial planning. The method involves eliciting a prior distribution for the treatment effect, and then calculating the probability that a proposed trial will produce a `successful' outcome. For normally distributed observations, uncertainty about the variance of the normal distribution also needs to be accounted for, but there is little guidance in the literature on how to elicit a distribution for a variance parameter. We present a simple elicitation method, and illustrate how the elicited distribution is incorporated within an assurance calculation. We also consider multi-stage trials, where a decision to proceed with a larger trial will follow from the outcome of a smaller trial; we illustrate the role of the elicted distribution in assessing the information provided by a proposed smaller trial. Free software is available for implementing our methods.

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Ziyad A. Alhussain, Jeremy E. Oakley. 2017-02-03. Assurance for clinical trial design with normally distributed outcomes: eliciting uncertainty about variances. https://arxiv.org/abs/1702.00978

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