Sample-size calculations for the Cox proportional hazards regression model with nonbinary covariates
Sample-size calculations for the Cox proportional hazards regression model with nonbinary covariates
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DOI：
10.1016/s0197-2456(00)00104-5
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发表时间：
2000-12-01
期刊：
影响因子：
--
通讯作者：
Lavori, PW
中科院分区：
文献类型：
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作者：
Hsieh, FY;Lavori, PW
本文导出了一个公式来计算具有非二元协变量的比例风险回归模型所需的死亡人数。该方法不需要假设生存时间和预测变量的分布，除了比例风险。模拟表明，在比例风险模型中，删减的观测值对检验的有效性没有贡献，这一事实对于二元协变量来说是众所周知的。本文还提供了一个方差膨胀因子以及在模型中包含额外协变量时调整样本量的模拟。(C) Elsevier Science Inc., 2000。
This paper derives a formula to calculate the number of deaths required for a proportional hazards regression model with a nonbinary covariate. The method does not require assumptions about the distributions of survival time and predictor variables other than proportional hazards. Simulations show that the censored observations do not contribute to the power of the test in the proportional hazards model, a fact that is well known for a binary covariate. This paper also provides a variance inflation factor together with simulations for adjustment of sample size when additional covariates are included in the model. (C) Elsevier Science Inc. 2000.