唐氏综合征筛查指标MoM值的正态性研究

Normality of MoM of screening indexes for Down's syndrome

目的考察江苏唐氏综合征产前筛查指标AFP和HCG的MoM值的正态性,探索Johnson分布体系中的SL分布族在上述指标正态性转换中应用的可行性和有效性.方法资料来自于江苏省出生缺陷干预项目研究,采用对数正态和Johnson分布体系中的SL正态性转换方法.结果两指标的MoM值均不服从正态分布;对数MoMHCG值以样本均数和标准差作为参数时,指标AFP的正态性较好,HCG仍不服从正态;Z=0.31时MoM指标SL转换后正态性明显改善.结论Johnson分布体系中SL分布族在我国唐氏综合征产前筛查指标HCG的MoM值的正态性转换中具有一定的应用价值.

AIM： To explore the normality of MoM values of AFP and HCG used to screen the Down＇s syndrome in Jiangsu province, and discuss the feasibility and effectiveness of application of SL transformation in Johnson system of distributions which is used to normalize MoM values of indexes above. METHODS： The data were obtained from the research project on birth defect intervention in Jiangsu province . SL transformation in lognormal distribution and Johnson distribution system was used to normalize MoM values of AFP and hCG in prenatal screening for Down＇s syndrome. RESULTS： The MoM values of AFP and HCG were both not of normal distribution. Through the lognormal distribution of MoM values, AFP was in accord with normal distribution and hCG was not. Normality of HCG MoM became better at Z = 0.31. CONCLUSION： It is suitable for the indexes of prenatal screening for Down＇s syndrome in our country to use SL normality transformation in Johnson system of distributions.