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Block response-adaptive randomization in clinical trials with binary endpoints

Magirr, Dominic (2011) Block response-adaptive randomization in clinical trials with binary endpoints. Pharmaceutical Statistics, 10 (4). pp. 341-346. ISSN 1539-1604

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Abstract

In a clinical trial, response-adaptive randomization (RAR) uses accumulating data to weigh the randomization of remaining patients in favour of the better performing treatment. The aim is to reduce the number of failures within the trial. However, many well-known RAR designs, in particular, the randomized play-the-winner-rule (RPWR), have a highly myopic structure which has sometimes led to unfortunate randomization sequences when used in practice. This paper introduces random permuted blocks into two RAR designs, the RPWR and sequential maximum likelihood estimation, for trials with a binary endpoint. Allocation ratios within each block are restricted to be one of 1:1, 2:1 or 3:1, preventing unfortunate randomization sequences. Exact calculations are performed to determine error rates and expected number of failures across a range of trial scenarios. The results presented show that when compared with equal allocation, block RAR designs give similar reductions in the expected number of failures to their unmodified counterparts. The reductions are typically modest under the alternative hypothesis but become more impressive if the treatment effect exceeds the clinically relevant difference

Item Type: Article
Journal or Publication Title: Pharmaceutical Statistics
Uncontrolled Keywords: adaptive designs ; randomized play-the-winner rule ; sequential maximum likelihood estimation ; random permuted blocks ; expected treatment failures
Subjects: Q Science > QA Mathematics
Departments: Faculty of Science and Technology > Mathematics and Statistics
ID Code: 59927
Deposited By: ep_importer_pure
Deposited On: 09 Nov 2012 10:59
Refereed?: Yes
Published?: Published
Last Modified: 09 Oct 2013 14:51
Identification Number:
URI: http://eprints.lancs.ac.uk/id/eprint/59927

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