患病人数未知时患病率估计的影响因素及其计算机模拟  

Factors Affecting the Estimation of Prevalence in the Absence of Patients Number by Computer Simulation

作　　者：滕海英[1] 祝国强[1] 刘沛[1] 

机构地区：[1]第二军医大学数理教研室,上海200433

出　　处：《数理医药学杂志》2011年第5期513-516,共4页Journal of Mathematical Medicine

摘　　要：目的:在患病人数未知的条件下,对患病率估计的影响因素。方法:利用计算机模拟和计算在不同的患病率、不同的病人分布和正常人分布、以及不同的临界点的条件下,患病率估计的最小误差所对应的诊断临界点,通过该最优临界点的变化规律揭示各影响因素的作用。结果:当实际患病率越高,或者病人和正常人均值间的差距越大,或者病人分布的方差越大时,需要提高诊断试验的灵敏度而降低特异度;当正常人分布的方差增大时,则需提高诊断试验的特异度而降低灵敏度。结论:对患病率的正确估计必须综合上述多种因素加以考虑。Objective： To study factors affecting the estimation of prevalence in the absence of patients number. Methods： The operating points with the minimal estimation error of prevalence were found by computer simulation under various prevalence, distributions of patients or healthy people and operating points. The variation laws of these optimal operating points showed the effect of all these factors. Results： In the higher prevalence, the greater discrepancy between means of patients and healthy people or the larger variance of patients distribution, it was suggested to improve sensitivity and reduce specificity in diagnostic test. On the contrary, specificity should be improved and sensitivity be reduced as the variance of normal people increases. Conclusion： All associated factors shall be considered to correctly estimate the prevalence.

关 键 词：患病率 灵敏度 特异度 临界点 阳性检出率 

分 类 号：R181.21[医药卫生—流行病学]