应用受试者操作特征曲线确立新生儿甲低筛查中TSH切值及召回参考值

Tsh cut-off point of neonatal congenital hypothyrodism screening

目的确立筛查新生儿先天性甲状腺功能低下症(con鄄genitalhypothyroidsm)中促甲状腺素(TSH)的诊断切值及召回参考值。方法采用时间分辨荧光免疫分析方法(DELFI鄄A),将随访的469例小儿的TSH连续变量,设定成不同的临界值,用受试者操作特征曲线(Receiveroperatingcharacteris鄄ticcurve)及曲线下面积(Areaunderthecurve)确定最佳临界值及评价试验的准确性。结果新生儿筛查CH的TSH最佳临界值为20mu/L,其敏感度为93.15%,特异度为89.14%,阳性预测值为61.3%,阴性预测值为95.65%,实验准确性为89.77%,阳性拟然比为8.58,召回复查率为1.45‰。次佳临界值为TSH为15mu/L,其敏感度为100%,特异度为80.56%,阳性预测值为48.7%,阴性预测值为100%,实验准确性为83.58%,阳性拟然比为5.14,召回复查率为2.0‰;百分位数法制定正常参考值TSH水平99%可信限在8.25mu/L以下,召回复查率为9.97‰;AUC为0.98。结论本法具有较高的准确性;新生儿筛查CH的TSH诊断切值为20mu/L,召回参考值为15mu/L,新生儿的TSH正常范围是≤8.25mu/L。

Objective To set up TSH cut-off point of neonatal congenital hypothyrodism (CH) screening.Methods By Dissociation-Enhanced Lantharide Fluoroimmvno Assay(DELFIA), to suppose different critical values according to 469 heonatal TSH continous variable,then decide the fittest critical value and evaluate test's accuracy according to receiver operating characterics curve(ROC) and area under curve(AUC).Results The sensitivity and specifity of testis different according to different TSH critical values the fittest critical value of neonatal CH screening TSH was 20 mu/L. The sencitivity was 93.15%, The specifity was 89.14%,the second fittest critical value was 15 mu/L,the sencitivity was 100%, The specifity was 80.56%,make out normalreference value which was below 8.25 mu/L in TSH level in 99% confidence interval according to percentile method.AUC was 0.98. Conclusion The test has high accuracy. The TSH cut-off value of nenonatal CH screening was 20 mu/L.thereference value was 15 mu/L.