Forced randomization: the what, why, and how

Abstract Background When running a randomized controlled trial (RCT), a clinical site may face a situation when an eligible trial participant is to be randomized to the treatment that is not available at the site. In this case, there are two options: not to enroll the participant, or, without disclo...

Full description

Saved in:
Bibliographic Details
Main Authors: Kerstine Carter, Olga Kuznetsova, Volodymyr Anisimov, Johannes Krisam, Colin Scherer, Yevgen Ryeznik, Oleksandr Sverdlov
Format: Article
Language:English
Published: BMC 2024-10-01
Series:BMC Medical Research Methodology
Subjects:
Online Access:https://doi.org/10.1186/s12874-024-02340-0
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1850163020875956224
author Kerstine Carter
Olga Kuznetsova
Volodymyr Anisimov
Johannes Krisam
Colin Scherer
Yevgen Ryeznik
Oleksandr Sverdlov
author_facet Kerstine Carter
Olga Kuznetsova
Volodymyr Anisimov
Johannes Krisam
Colin Scherer
Yevgen Ryeznik
Oleksandr Sverdlov
author_sort Kerstine Carter
collection DOAJ
description Abstract Background When running a randomized controlled trial (RCT), a clinical site may face a situation when an eligible trial participant is to be randomized to the treatment that is not available at the site. In this case, there are two options: not to enroll the participant, or, without disclosing to the site, allocate the participant to a treatment arm with drug available at the site using a built-in feature of the interactive response technology (IRT). In the latter case, one has employed a “forced randomization” (FR). There seems to be an industry-wide consensus that using FR can be acceptable in confirmatory trials provided there are “not too many” instances of forcing. A better understanding of statistical properties of FR is warranted. Methods We described four different IRT configurations with or without FR and illustrated them using a simple example. We discussed potential merits of FR and outlined some relevant theoretical risks and risk mitigation strategies. We performed a search using Cortellis Regulatory Intelligence database (IDRAC) ( www.cortellis.com ) to understand the prevalence of FR in clinical trial practice. We also proposed a structured template for development and evaluation of randomization designs featuring FR and showcased an application of this template for a hypothetical multi-center 1:1 RCT under three experimental settings (“base case”, “slower recruitment”, and “faster recruitment”) to explore the effect of four different IRT configurations in combination with three different drug supply/re-supply strategies on some important operating characteristics of the trial. We also supplied the Julia code that can be used to reproduce our simulation results and generate additional results under user-specified experimental scenarios. Results FR can eliminate refusals to randomize patients, which can cause frustration for patients and study site personnel, improve the study logistics, drug supply management, cost-efficiency, and recruitment time. Nevertheless, FR carries some potential risks that should be reviewed at the study planning stage and, ideally, prospectively addressed through risk mitigation planning. The Cortellis search identified only 9 submissions that have reported the use of FR; typically, the FR option was documented in IRT specifications. Our simulation evidence showed that under the considered realistic experimental settings, the percentage of FR is expected to be low. When FR with backfilling was used in combination with high re-supply strategy, the final treatment imbalance was negligibly small, the proportion of patients not randomized due to the lack of drug supply was close to zero, and the time to complete recruitment was shortened compared to the case when FR was not allowed. The drug overage was primarily determined by the intensity of the re-supply strategy and to a smaller extent by the presence or absence of the FR feature in IRT. Conclusion FR with a carefully chosen drug supply/re-supply strategy can result in quantifiable improvements in the patients’ and site personnel experience, trial logistics and efficiency while preventing an undesirable refusal to randomize a patient and a consequential unblinding at the site. FR is a useful design feature of multi-center RCTs provided it is properly planned for and carefully implemented.
format Article
id doaj-art-6409d535618d494eb89ff5cf9a7acc55
institution OA Journals
issn 1471-2288
language English
publishDate 2024-10-01
publisher BMC
record_format Article
series BMC Medical Research Methodology
spelling doaj-art-6409d535618d494eb89ff5cf9a7acc552025-08-20T02:22:24ZengBMCBMC Medical Research Methodology1471-22882024-10-0124112210.1186/s12874-024-02340-0Forced randomization: the what, why, and howKerstine Carter0Olga Kuznetsova1Volodymyr Anisimov2Johannes Krisam3Colin Scherer4Yevgen Ryeznik5Oleksandr Sverdlov6Boehringer-Ingelheim Pharmaceuticals IncMerck & Co., Inc.Amgen Ltd.Boehringer-Ingelheim Pharma GmbH & Co. KGRensselaer Polytechnic InstituteDepartment of Pharmacy, Uppsala UniversityNovartis Pharmaceuticals CorporationAbstract Background When running a randomized controlled trial (RCT), a clinical site may face a situation when an eligible trial participant is to be randomized to the treatment that is not available at the site. In this case, there are two options: not to enroll the participant, or, without disclosing to the site, allocate the participant to a treatment arm with drug available at the site using a built-in feature of the interactive response technology (IRT). In the latter case, one has employed a “forced randomization” (FR). There seems to be an industry-wide consensus that using FR can be acceptable in confirmatory trials provided there are “not too many” instances of forcing. A better understanding of statistical properties of FR is warranted. Methods We described four different IRT configurations with or without FR and illustrated them using a simple example. We discussed potential merits of FR and outlined some relevant theoretical risks and risk mitigation strategies. We performed a search using Cortellis Regulatory Intelligence database (IDRAC) ( www.cortellis.com ) to understand the prevalence of FR in clinical trial practice. We also proposed a structured template for development and evaluation of randomization designs featuring FR and showcased an application of this template for a hypothetical multi-center 1:1 RCT under three experimental settings (“base case”, “slower recruitment”, and “faster recruitment”) to explore the effect of four different IRT configurations in combination with three different drug supply/re-supply strategies on some important operating characteristics of the trial. We also supplied the Julia code that can be used to reproduce our simulation results and generate additional results under user-specified experimental scenarios. Results FR can eliminate refusals to randomize patients, which can cause frustration for patients and study site personnel, improve the study logistics, drug supply management, cost-efficiency, and recruitment time. Nevertheless, FR carries some potential risks that should be reviewed at the study planning stage and, ideally, prospectively addressed through risk mitigation planning. The Cortellis search identified only 9 submissions that have reported the use of FR; typically, the FR option was documented in IRT specifications. Our simulation evidence showed that under the considered realistic experimental settings, the percentage of FR is expected to be low. When FR with backfilling was used in combination with high re-supply strategy, the final treatment imbalance was negligibly small, the proportion of patients not randomized due to the lack of drug supply was close to zero, and the time to complete recruitment was shortened compared to the case when FR was not allowed. The drug overage was primarily determined by the intensity of the re-supply strategy and to a smaller extent by the presence or absence of the FR feature in IRT. Conclusion FR with a carefully chosen drug supply/re-supply strategy can result in quantifiable improvements in the patients’ and site personnel experience, trial logistics and efficiency while preventing an undesirable refusal to randomize a patient and a consequential unblinding at the site. FR is a useful design feature of multi-center RCTs provided it is properly planned for and carefully implemented.https://doi.org/10.1186/s12874-024-02340-0Drug supply chain managementInteractive response technology (IRT)Multi-center clinical trialPoisson-gamma model
spellingShingle Kerstine Carter
Olga Kuznetsova
Volodymyr Anisimov
Johannes Krisam
Colin Scherer
Yevgen Ryeznik
Oleksandr Sverdlov
Forced randomization: the what, why, and how
BMC Medical Research Methodology
Drug supply chain management
Interactive response technology (IRT)
Multi-center clinical trial
Poisson-gamma model
title Forced randomization: the what, why, and how
title_full Forced randomization: the what, why, and how
title_fullStr Forced randomization: the what, why, and how
title_full_unstemmed Forced randomization: the what, why, and how
title_short Forced randomization: the what, why, and how
title_sort forced randomization the what why and how
topic Drug supply chain management
Interactive response technology (IRT)
Multi-center clinical trial
Poisson-gamma model
url https://doi.org/10.1186/s12874-024-02340-0
work_keys_str_mv AT kerstinecarter forcedrandomizationthewhatwhyandhow
AT olgakuznetsova forcedrandomizationthewhatwhyandhow
AT volodymyranisimov forcedrandomizationthewhatwhyandhow
AT johanneskrisam forcedrandomizationthewhatwhyandhow
AT colinscherer forcedrandomizationthewhatwhyandhow
AT yevgenryeznik forcedrandomizationthewhatwhyandhow
AT oleksandrsverdlov forcedrandomizationthewhatwhyandhow