Fajardo-Gutiérrez A, Yamamoto-Kimura L, Yáñez-Velasco L, Garduño-Espinosa J, Martínez-García M C
Departamento de Epidemiología Clínica, Instituto Mexicano del Seguro Social, Hospital de Pediatría, Centro Médico Nacional.
Salud Publica Mex. 1994 May-Jun;36(3):311-7.
The aim of this study was to obtain the cut point to determine an individual's seronegativity with respect to measles using commercial reagents. To determine the test sensitivity, the serum of 22 individuals 21 years of age or older, and a positive history of measles (positive control group) was studied. For specificity, the serum of 22 children 15 to 24 months old, and no measles vaccination record nor positive history of measles (negative control group), was analyzed. The antibodies titer determination for both groups was done using the ELISA technique and the Brunell method, subsequently, as well as a ROC curve (Received Operating Curve). When the Brunell method was used, the cut points were 0.4090 (sensitivity 1.0 and specificity 0.95) and 0.5042 (sensitivity 0.95 and specificity 1.0). When a ROC curve was done the cut point was 0.4500, with a sensitivity and specificity of 100 per cent. It was also concluded that the latter is the best method to obtain this cut point, because it does not establish arbitrary values when the data distribution does not follow a normal pattern.
本研究的目的是使用商业试剂获得用于确定个体麻疹血清学阴性的临界值。为了确定检测灵敏度，研究了22名21岁及以上且有麻疹阳性病史的个体的血清（阳性对照组）。为了确定特异性，分析了22名15至24个月大、无麻疹疫苗接种记录且无麻疹阳性病史的儿童的血清（阴性对照组）。随后，使用ELISA技术和布鲁内尔方法对两组的抗体滴度进行了测定，并绘制了受试者工作特征曲线（ROC曲线）。使用布鲁内尔方法时，临界值分别为0.4090（灵敏度1.0，特异性0.95）和0.5042（灵敏度0.95，特异性1.0）。绘制ROC曲线时，临界值为0.4500，灵敏度和特异性均为100%。还得出结论，后者是获得该临界值的最佳方法，因为当数据分布不呈正态分布时，它不会设定任意值。
