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Published in: Trials 1/2017

Open Access 01-12-2017 | Research

Minimal sufficient balance randomization for sequential randomized controlled trial designs: results from the ESCAPE trial

Authors: Tolulope T. Sajobi, Gurbakhshash Singh, Mark W. Lowerison, Jordan Engbers, Bijoy K. Menon, Andrew M. Demchuk, Mayank Goyal, Michael D. Hill

Published in: Trials | Issue 1/2017

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Abstract

Background

We describe the implementation of minimal sufficient balance randomization, a covariate-adaptive randomization technique, used for the “Endovascular treatment for Small Core and Anterior circulation Proximal occlusion with Emphasis on minimizing CT to recanalization times” (ESCAPE) trial.

Methods

The ESCAPE trial is a prospective, multicenter, randomized clinical trial that enrolled subjects with the following main inclusion criteria: less than 12 h from symptom onset, age 18 years or older, baseline NIHSS score > 5, ASPECTS score > 5 and computed tomography angiography (CTA) evidence of carotid T/L or M1-segment middle cerebral artery (MCA) occlusion, and at least moderate collaterals by CTA. Patients were randomized using a real-time, dynamic, Internet-based, minimal sufficient balance randomization method that balanced the study arms with respect to baseline covariates including age, sex, baseline NIHSS score, site of arterial occlusion, baseline ASPECTS score and treatment with intravenously administered alteplase.

Results

Permutation-based tests of group differences confirmed group balance across several baseline covariates including sex (p = 1.00), baseline NIHSS score (p = 0.95), site of arterial occlusion (p = 1.00), baseline ASPECTS score (p = 0.28), treatment with intravenously administered alteplase (p = 0.31), and age (p = 0.67).

Conclusion

Results from the ESCAPE trial demonstrate the feasibility and the benefit of this covariate adaptive randomization scheme in small-sample trials and for data monitoring endeavors.

Trial registration

ESCAPE trial – NCT01778335 – at www.​clinicaltrials.​gov. Registered on 29 January 2013.
Appendix
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Metadata
Title
Minimal sufficient balance randomization for sequential randomized controlled trial designs: results from the ESCAPE trial
Authors
Tolulope T. Sajobi
Gurbakhshash Singh
Mark W. Lowerison
Jordan Engbers
Bijoy K. Menon
Andrew M. Demchuk
Mayank Goyal
Michael D. Hill
Publication date
01-12-2017
Publisher
BioMed Central
Published in
Trials / Issue 1/2017
Electronic ISSN: 1745-6215
DOI
https://doi.org/10.1186/s13063-017-2264-1

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