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Two-to-One Randomization: Rarely Advisable
Boris Freidlin1, Edward L Korn1
1Biometric Research Program, Division of Cancer Treatment and Diagnosis, National Cancer Institute, Bethesda, MD.
JCO Oncology Practice
|July 10, 2024
Summary
Some oncology trials use two-to-one randomization, assigning more patients to experimental treatments. This commentary questions the assumed favorable risk-benefit ratio of this common oncology trial design.
Area of Science:
- Oncology
- Clinical Trials
- Biostatistics
Background:
- Randomized clinical trials (RCTs) commonly allocate equal patient numbers to treatment arms.
- Some oncology trials deviate by using unequal allocation, such as two-to-one randomization, favoring the experimental arm.
Purpose of the Study:
- To review common justifications for two-to-one randomization in oncology trials.
- To critically evaluate the risk-benefit ratio of this non-standard randomization approach.
Main Methods:
- Review of existing literature and common practices in oncology clinical trial design.
- Analysis of the implications of two-to-one randomization on risk-benefit assessment.
Main Results:
- Identifies frequent reasons cited for employing two-to-one randomization.
- Challenges the assumption that this design inherently offers a favorable risk-benefit balance.
Conclusions:
- The perceived advantages of two-to-one randomization in oncology may not always outweigh potential disadvantages.
- Further scrutiny of risk-benefit ratios is warranted for trials using unequal randomization schemes.
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