ReviewContemporary clinical trials2011
Block urn design - a new randomization algorithm for sequential trials with two or more treatments and balanced or unbalanced allocation.
Review in Contemporary clinical trials, 2011. The graph could read no effect estimate from its abstract, so it casts no vote on the map. It is linked to trial NCT06705764 (Tezepelumab in the Treatment of Emergency Room Asthma in Adults), which is not on this map. Cited by 26 papers.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Tezepelumab in the Treatment of Emergency Room Asthma in Adults (TERAA): A Phase 4 Double-Blinded, Parallel-Group, Randomized Control Trial With an Open Label Extension
Who cites it
26 citing papers in PubMed.
- HealthCall: Smartphone Enhancement of Brief Interventions to Improve HIV Medication Adherence Among Patients in HIV Care.AIDS and behavior · 2024Trial
- Improving Children's Behavior in Seven Sessions: A Randomized Controlled Trial of Parent-Child Care (PC-CARE) for Children Aged 2-10 Years.Child psychiatry and human development · 2024Trial
- Selecting a randomization method for a multi-center clinical trial with stochastic recruitment considerations.BMC medical research methodology · 2024Trial
- HealthCall: A randomized trial assessing a smartphone enhancement of brief interventions to reduce heavy drinking in HIV care.Journal of substance abuse treatment · 2022Trial
- A roadmap to using randomization in clinical trials.BMC medical research methodology · 2021Trial
- Trial
- Effect of High-Intensity Treadmill Exercise on Motor Symptoms in Patients With De Novo Parkinson Disease: A Phase 2 Randomized Clinical Trial.JAMA neurology · 2018Trial
- Reducing selection bias risk to enhance RCT validity: sandwich mixed randomization outperforms permuted block design.BMC medical research methodology · 2026Article
- Minimization of expected balance distribution differences: optimization of the randomized allocation algorithm based on the Pocock-Simon design.BMC medical research methodology · 2026Article
- Accurate and efficient P-values for rank-based independence tests with clustered data using a saddlepoint approximation.Scientific reports · 2025Article
- Randomization in the age of platform trials: unexplored challenges and some potential solutions.BMC medical research methodology · 2025Review
- Allocation Predictability of Individual Assignments in Restricted Randomization Designs for Two-Arm Equal Allocation Trials.Statistics in medicine · 2025Article
- Forced randomization: the what, why, and how.BMC medical research methodology · 2024Article
- Steady-state statistical properties and implementation of randomization designs with maximum tolerated imbalance restriction for two-arm equal allocation clinical trials.Statistics in medicine · 2024Article
- Comparison of Pocock and Simon's covariate-adaptive randomization procedures in clinical trials.BMC medical research methodology · 2024Article
- Review
- Review
- Implementing Optimal Designs for Dose-Response Studies Through Adaptive Randomization for a Small Population Group.The AAPS journal · 2018Article
- Generalization of Wei's urn design to unequal allocations in sequential clinical trials.Contemporary clinical trials communications · 2016Article
- Characterizing permuted block randomization as a big stick procedure.Contemporary clinical trials communications · 2016Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
2 authors.
Funding
Abstract
Permuted block design is the most popular randomization method used in clinical trials, especially for trials with more than two treatments and unbalanced allocation, because of its consistent imbalance control and simplicity in implementation. However, the risk of selection biases caused by high proportion of deterministic assignments is a cause of concern. Efron's biased coin design and Wei's urn design provide better allocation randomness without deterministic assignments, but they do not consistently control treatment imbalances. Alternative randomization designs with improved performances have been proposed over the past few decades, including Soares and Wu's big stick design, which has high allocation randomness, but is limited to two-treatment balanced allocation scenarios only, and Berger's maximal procedure design which has a high allocation randomness and a potential for more general trial scenarios, but lacks the explicit function for the conditional allocation probability and is more complex to implement than most other designs. The block urn design proposed in this paper combines the advantages of existing randomization designs while overcoming their limitations. Statistical properties of the new algorithm are assessed and compared to currently available designs via analytical and computer simulation approaches. The results suggest that the block urn design simultaneously provides consistent imbalance control and high allocation randomness. It can be easily implemented for sequential clinical trials with two or more treatments and balanced or unbalanced allocation.
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Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.