病例对照研究评价疫苗效力的样本含量

目的 提出一种病例对照研究设计中可调区可信区间精度的评价疫苗效力（VE）所需样本含量的计算公式。方法：应用可信区间相对宽度原理推导计算公式。结果 预设的相对宽度可调节和控制可信区间精度并决定样本含量的大小。结论 使研究者能较为准确地掌握VE点估计值接近总体真实值的程度。

Sample sizes to Estimate Vaccine Efficacy in Case-Control Study

Objective This paper presents formula for determining the sample size required in case-control study to estimate vaccine efficacy VE with adjusting the precision of confidence interval.Methods Formula to calculate sample size is derived from the principle of relative width of the confidence interval.Results Prespecified relative width may regulate and control the precision of confidence interval and may reflects magnitude of the sample size.Conclusion Sample size calculated by formula will assure that the investigator understand accurately the degree of point estimates of VE close to the true value of VE in the population.