Assessment of Type I Error Rate Associated with Dose-Group Switching in a Longitudinal Alzheimer Trial

作者:Ghebretinsae Aklilu Habteab*; Molenberghs Geert; Dmitrienko Alex; Offen Walt; Sethuraman Gopalan
来源:Journal of Biopharmaceutical Statistics, 2014, 24(3): 660-684.
DOI:10.1080/10543406.2014.888570

摘要

In clinical trials, there always is the possibility to use data-driven adaptation at the end of a study. There prevails, however, concern on whether the type I error rate of the trial could be inflated with such design, thus, necessitating multiplicity adjustment. In this project, a simulation experiment was set up to assess type I error rate inflation associated with switching dose group as a function of dropout rate at the end of the study, where the primary analysis is in terms of a longitudinal outcome. This simulation is inspired by a clinical trial in Alzheimer%26apos;s disease. The type I error rate was assessed under a number of scenarios, in terms of differing correlations between efficacy and tolerance, different missingness mechanisms, and different probabilities of switching. A collection of parameter values was used to assess sensitivity of the analysis. Results from ignorable likelihood analysis show that the type I error rate with and without switching was approximately the posited error rate for the various scenarios. Under last observation carried forward (LOCF), the type I error rate blew up both with and without switching. The type I error inflation is clearly connected to the criterion used for switching. While in general switching, in a way related to the primary endpoint, may impact the type I error, this was not the case for most scenarios in the longitudinal Alzheimer trial setting under consideration, where patients are expected to worsen over time.

  • 出版日期2014-5-4

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