可加风险模型现状数据样本量的确定

Sample Size Determination for the Additive Hazards Model with Current Status Data

科学研究中,样本量和功效计算是非常重要的工作。可加风险模型是生存分析研究中经常用到的半参数模型,其协变量对基础风险函数有加法作用。和比例风险模型相比,可加风险模型在许多应用中效果更好,尤其是协变量取值为0或1时。本文基于Wald检验,提出一种计算可加风险模型现状数据功效和样本量的新方法。模拟结果说明该计算方法十分有效。另外,本文通过1个实际例子展示新方法的应用。

Power and sample size calculations are important and necessary parts in the design stage of a scientific study.In the failure time data analysis,the additive hazards model,which specifies that the covariates have an additive effect on the baseline risk,is one of the most popular used semiparametric models.Compared with the proportional hazards model,the additive hazards model would be more plausible in many applications,especially in the two-sample situation where the covariate takes value only 0 or 1.In this paper,a novel method is proposed for calculating power and sample size for the additive hazards model with current status data based on the Wald test.The simulation studies demonstrate that the proposed sample size formula is adequate.Moreover,a real example is presented to illustrate the application of the proposed formula.