Characterizing permuted block randomization as a big stick procedure

There are numerous approaches to randomizing patients to treatment groups in clinical trials. The most popular is permuted block randomization, and a newer and better class, which is gaining in popularity, is the so-called class of MTI procedures, which use a big stick to force the allocation sequen...

Full description

Bibliographic Details
Main Authors: Vance W. Berger, Isoken Odia
Format: Article
Language:English
Published: Elsevier 2016-04-01
Series:Contemporary Clinical Trials Communications
Subjects:
Online Access:http://www.sciencedirect.com/science/article/pii/S2451865415300223
_version_ 1819061197370032128
author Vance W. Berger
Isoken Odia
author_facet Vance W. Berger
Isoken Odia
author_sort Vance W. Berger
collection DOAJ
description There are numerous approaches to randomizing patients to treatment groups in clinical trials. The most popular is permuted block randomization, and a newer and better class, which is gaining in popularity, is the so-called class of MTI procedures, which use a big stick to force the allocation sequence back towards balance when it reaches the MTI (maximally tolerated imbalance). Three prominent members of this class are the aptly named big stick procedure, Chen's procedure, and the maximal procedure. As we shall establish in this article, blocked randomization, though not typically cast as an MTI procedure, does in fact use the big stick as well. We shall argue that its weaknesses, which are well known, arise precisely from its improper use, bordering on outright abuse, of this big stick. Just as rocket powered golf clubs add power to a golf swing, so too does the big stick used by blocked randomization hit with too much power. In addition, the big stick is invoked when it need not be, thereby resulting in the excessive prediction for which permuted blocks are legendary. We bridge the gap between the MTI procedures and block randomization by identifying a new randomization procedure intermediate between the two, namely based on an excessively powerful big stick, but one that is used only when needed. We shall then argue that the MTI procedures are all superior to this intermediate procedure by virtue of using a restrained big stick, and that this intermediate procedure is superior to block randomization by virtue of restraint in when the big stick is invoked. The transitivity property then completes our argument.
first_indexed 2024-12-21T14:39:03Z
format Article
id doaj.art-ecd885e94cf44bb8b092e8877bde25a7
institution Directory Open Access Journal
issn 2451-8654
language English
last_indexed 2024-12-21T14:39:03Z
publishDate 2016-04-01
publisher Elsevier
record_format Article
series Contemporary Clinical Trials Communications
spelling doaj.art-ecd885e94cf44bb8b092e8877bde25a72022-12-21T19:00:15ZengElsevierContemporary Clinical Trials Communications2451-86542016-04-012C808410.1016/j.conctc.2016.01.001Characterizing permuted block randomization as a big stick procedureVance W. Berger0Isoken Odia1National Cancer Institute and University of Maryland Baltimore County, Biometry Research Group, National Cancer Institute, 9609 Medical Center Drive, Rockville, MD 20850, USAUniversity of South Florida, 13301 Bruce B. Downs Boulevard, Tampa, FL 33612, USAThere are numerous approaches to randomizing patients to treatment groups in clinical trials. The most popular is permuted block randomization, and a newer and better class, which is gaining in popularity, is the so-called class of MTI procedures, which use a big stick to force the allocation sequence back towards balance when it reaches the MTI (maximally tolerated imbalance). Three prominent members of this class are the aptly named big stick procedure, Chen's procedure, and the maximal procedure. As we shall establish in this article, blocked randomization, though not typically cast as an MTI procedure, does in fact use the big stick as well. We shall argue that its weaknesses, which are well known, arise precisely from its improper use, bordering on outright abuse, of this big stick. Just as rocket powered golf clubs add power to a golf swing, so too does the big stick used by blocked randomization hit with too much power. In addition, the big stick is invoked when it need not be, thereby resulting in the excessive prediction for which permuted blocks are legendary. We bridge the gap between the MTI procedures and block randomization by identifying a new randomization procedure intermediate between the two, namely based on an excessively powerful big stick, but one that is used only when needed. We shall then argue that the MTI procedures are all superior to this intermediate procedure by virtue of using a restrained big stick, and that this intermediate procedure is superior to block randomization by virtue of restraint in when the big stick is invoked. The transitivity property then completes our argument.http://www.sciencedirect.com/science/article/pii/S2451865415300223Big stickBlocked randomizationMaximal procedure
spellingShingle Vance W. Berger
Isoken Odia
Characterizing permuted block randomization as a big stick procedure
Contemporary Clinical Trials Communications
Big stick
Blocked randomization
Maximal procedure
title Characterizing permuted block randomization as a big stick procedure
title_full Characterizing permuted block randomization as a big stick procedure
title_fullStr Characterizing permuted block randomization as a big stick procedure
title_full_unstemmed Characterizing permuted block randomization as a big stick procedure
title_short Characterizing permuted block randomization as a big stick procedure
title_sort characterizing permuted block randomization as a big stick procedure
topic Big stick
Blocked randomization
Maximal procedure
url http://www.sciencedirect.com/science/article/pii/S2451865415300223
work_keys_str_mv AT vancewberger characterizingpermutedblockrandomizationasabigstickprocedure
AT isokenodia characterizingpermutedblockrandomizationasabigstickprocedure