基于内部预试验方差及组间差值的样本量调整模拟  

Simulation of sample size adjustment using the sample variance and the observed treatment difference based on internal pilot study

作　　者：王素珍[1] 孟维静[1] 吕军城[1] 石福艳[1] 夏结来[2] 

机构地区：[1]潍坊医学院卫生统计学教研室,山东省潍坊市261053 [2]第四军医大学卫生统计学教研室

出　　处：《中国医院统计》2012年第3期169-172,共4页Chinese Journal of Hospital Statistics

基　　金：国家自然科学基金项目（81141112,30671823）,山东省卫生厅基金项目（2009HW103）

摘　　要：目的 通过盲态下内部预试验IPS样本量调整的模拟分析,探索协变量存在前提下有效控制Ⅰ型错误、保证检验效能的合理统计方法.方法 利用蒙特-卡罗法模拟存在协变量时的两阶段自适应设计过程,分别采用协方差分析法和方差分析法分析两阶段数据,采用合并P值法确定检验的最终结果,比较两种方法对Ⅰ型错误、检验效能值的影响.结果 采用方差分析的Ⅰ型错误膨胀较协方差分析要大,检验效能也较协方差分析略低,但是Ⅰ型错误的增大更明显.结论 根据第一阶段的方差和组间均值差调整样本量时,如果存在协变量,应采用协方差分析方法分别分析第一、二阶段的数据,然后采用合并P值法做出统计推断.Objective To determine the appropriate methods to control the inflation of type I error and the lowering of power on the condition of existing covariance through simulations of analysis for internal pilot study in clinical trials. Methods Two-stage design with covariance was simulated by Monte Carlo methods. Both ANCOVA （Analysis of Covariance） and ANOVA （ Analysis of Variance） were used to analyze the two-stage data. Fisher＇s Combination P test was used to make the final reference in order to compare the different effect of two methods on type I error and power. Results Type I error of ANOVA was lager than that of ANCOVA, and the power of ANOVA was lower. The inflation of the Type I error was more obvious and should be paid more attention. Conclusion ANCOVA should be used to make analysis of the data of the first and the second stage respec- tively, and Combination P test should be used to make the final analysis with condition of existing covariable.

关 键 词：样本量调整 临床试验 内部预试验 蒙特-卡罗模拟 检验效能 

分 类 号：R195.1[医药卫生—卫生统计学]