Randomization in clinical studies
Open accessAbstract
Randomized controlled trial is widely accepted as the best design for evaluating the efficacy of a new treatment because of the advantages of randomization (random allocation). Randomization eliminates accidental bias, including selection bias, and provides a base for allowing the use of probability theory. Despite its importance, randomization has not been properly understood. This article introduces the different randomization methods with examples: simple randomization; block randomization; adaptive randomization, including minimization; and response-adaptive randomization. Ethics related to randomization are also discussed. The study is helpful in understanding the basic concepts of randomization and how to use R software.
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Permuted-block randomization followed established allocation principles for balancing treatment groups.
“Permuted-block randomization followed established allocation principles for balancing treatment groups (Lim and In, 2019).”
From Responsible use of generative AI in Chinese vocational education: eye-tracking evidence on source verification and immediate near-transfer across three information-seeking conditions (2026) · cites this paper as Lim and In, 2019
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Cites
Generation of allocation sequences in randomised trials: chance, not choice
Schulz, K. F., & Grimes, D. A. (2002) · The Lancet · doi:10.1016/s0140-6736(02)07683-3 · Cited by 774 · see citing works
Stratified Randomization for Clinical Trials
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Randomization in clinical trials: Conclusions and recommendations
Lachin, J. M., Matts, J. P., & Wei, L. J. (1988) · Controlled Clinical Trials · doi:10.1016/0197-2456(88)90049-9 · Cited by 272 · see citing works
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Quantifying representativeness in randomized clinical trials using machine learning fairness metrics
Qi, M., Cahan, O., Foreman, M. A., Gruen, D. M., Das, A. K., & Bennett, K. P. (2021) · JAMIA Open · doi:10.1093/jamiaopen/ooab077 · Cited by 27 · see citing works
Ma, J., Yue, H., & Li, X. (2026) · Frontiers in Psychology · doi:10.3389/fpsyg.2026.1946196
- Authors
- Lim, C.-Y., & In, J.
- Affiliations
- Dongguk University (KR)
- Dongguk University Ilsan Hospital (KR)
- Corresponding author
- In, Junyong
- Venue
- Korean Journal of Anesthesiology
- Published
- 2019-06-01
- Volume
- 72
- Issue
- 3
- Pages
- 221-232
- ISSN
- 0302-5780 (ISSN-L)
- 2005-6419
- 2005-7563
- PMC
- PMC6547231
- OpenAlex
- W2933062038
- Cited by
- 307
- References
- 3
- Citations by year
- 2026: 41 · 2025: 60 · 2024: 74 · 2023: 50 · 2022: 42 · 2021: 29 · 2020: 10 · 2019: 1
- FWCI
- 16.04
- Type
- journal article
- Language
- en
- Update notices
- correction (2019-07-30)
- Open access
- diamond
- doi.org
- Licence
- Locations
- Korean Journal of Anesthesiology (publishedVersion, cc-by-nc)
- PubMed Central (publishedVersion, cc-by-nc)
- PubMed (publishedVersion)
- DOAJ (DOAJ: Directory of Open Access Journals) (submittedVersion, cc-by-sa)
- Topics
- Physical Sciences › Mathematics › Statistics and Probability › Statistical Methods in Clinical Trials
- Social Sciences › Decision Sciences › Management Science and Operations Research › Optimal Experimental Design Methods
- Physical Sciences › Mathematics › Statistics and Probability › Advanced Causal Inference Techniques
- Keywords
- randomization, block randomization, adaptive randomization, minimization, response-adaptive randomization, selection bias, R software
- MeSH terms
- Humans, Random Allocation, Research Design, Bias, Selection Bias, Randomized Controlled Trials as Topic
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