【摘要】 提出了在确定可信区间概率时选择较高精度估计病例对照研究中 OR和队列研究中 RR所需样本含量的公式。由公式计算的样本含量能使研究者了解由样本所获得的点估计值接近总体真实值的程度 ,从而能较为准确地判断研究结果的实际意义。更多还原

【Abstract】 This paper presents formulae for determining the number of subjects necessary, in either a case-control or cohort study, to estimate the odds ratio or relative risk, respectvely, to within a selected precision of the true population value with some stated probability. Sample sizes calculated by formulae will assure that the investigstor comprehend directly the precision of point estimates close to the actual measure of effect in the population and judge accurately practical meaning of research resulting.更多还原