The method of minimization for random allocation in clinical trials:introduction and its SAS program
Zhao Lijun, Li Hongtian, Duan Feifan, Liao Zijun, Zhou Yubo, Liu Jianmeng
Institute of Reproductive and Child Health / Ministry of Health Key Laboratory of Reproductive Health, Department of Epidemiology and Biostatistics, School of Public Health, Peking University, Beijing 100191, China
Abstract：Objective To introduce the basic principle and operation process of minimization, and compile a customized SAS macro program. Methods Through literature review, the basic principle and operation process of minimization were summarized. By using a simulation example, we introduced a customized SAS macro program of minimization, and the results of allocation for the simulation example were provided. Results As a dynamic randomization method, minimization assigned the next patient into treatment groups with dynamic probability which depended on the balance of some prognostic factors, in order to achieve well-balanced groups. The assignment depended on three functions: the factor level imbalance function, the total imbalance function, and the optimal allocation probabilities. Although the method of minimization has advantages compared with other methods of randomization, its application has been limited probably because of the relatively complicated implementation procedure. As demonstrated by the simulated example, the utilization of minimization could be simplified by using the customized SAS macro. Conclusion Minimization was a method suitable for clinical trials with small sample and complex baseline characteristics. The SAS macro program could simplify the implementation process and facilitate the application of minimization.
赵丽君, 李宏田, 段蜚藩, 廖紫珺, 周玉博, 刘建蒙. 最小化随机分组方法介绍及其SAS实现[J]. 中国生育健康杂志, 2018, 29(2): 101-105.
Zhao Lijun, Li Hongtian, Duan Feifan, Liao Zijun, Zhou Yubo, Liu Jianmeng. The method of minimization for random allocation in clinical trials:introduction and its SAS program. Chinese Journal of Reproductive Health, 2018, 29(2): 101-105.
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