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Balance algorithm for cluster randomized trials

Carter, Ben Richard and Hood, Kerenza 2008. Balance algorithm for cluster randomized trials. BMC Medical Research Methodology 8 (1) , 65. 10.1186/1471-2288-8-65

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Background Within cluster randomized trials no algorithms exist to generate a full enumeration of a block randomization, balancing for covariates across treatment arms. Furthermore, often for practical reasons multiple blocks are required to fully randomize a study, which may not have been well balanced within blocks. Results We present a convenient and easy to use randomization tool to undertake allocation concealed block randomization. Our algorithm highlights allocations that minimize imbalance between treatment groups across multiple baseline covariates. We demonstrate the algorithm using a cluster randomized trial in primary care (the PRE-EMPT Study) and show that the software incorporates a trade off between independent random allocations that were likely to be imbalanced, and predictable deterministic approaches that would minimise imbalance. We extend the methodology of single block randomization to allocate to multiple blocks conditioning on previous allocations. Conclusion The algorithm is included as Additional file 1 and we advocate its use for robust randomization within cluster randomized trials.

Item Type: Article
Date Type: Publication
Status: Published
Schools: Medicine
Subjects: R Medicine > RA Public aspects of medicine
Publisher: BioMed Central
ISSN: 1471-2288
Funders: NIHR
Date of First Compliant Deposit: 22 August 2018
Last Modified: 22 Aug 2018 12:30

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