Jensen J E, Nielsen S H, Foged L, Holmegaard S N, Magid E
Department of Clinical Chemistry, Sundby Hospital, Copenhagen, Denmark.
Scand J Clin Lab Invest. 1996 Apr;56(2):117-22. doi: 10.3109/00365519609088597.
The MICRAL test is an immunospecific dipstick for detection of low concentrations of albumin in urine (microalbuminuria). The test is intended to be used for screening in an ambulatory setting. The utility of the test depends on its ability to accurately predict which patients will be classified as either microalbuminuric or normoalbuminuric by means of a standard laboratory method for determination of albumin in urine. We have analysed data from studies with a total of 2904 samples of urine from diabetic patients. The data are from our own study (190 samples) and from a selected set of 10 publications. The results from standard laboratory measurements of albumin in urine were used as " gold standards". The sensitivity and specificity as calculated from the pooled data were 83.2 and 92.3%, respectively. The predictive values were calculated using simulated changes in the prevalence of microalbuminuria (MAU). At a prevalence of MAU of 1% the predictive value of a negative test is 99.9% but that of a positive test only 9.8%. At a prevalence of MAU of 80% the positive predictive value is 97.7% and the negative predictive value 57.9%. In general, any change in the prevalence will lead to a change in the predictive values. Thus the prevalence of MAU in the given clinical setting is a decisive factor in determining the utility of the MICRAL test.
MICRAL检测是一种用于检测尿液中低浓度白蛋白（微量白蛋白尿）的免疫特异性试纸条。该检测旨在用于门诊环境中的筛查。该检测的效用取决于其通过标准实验室方法测定尿液中白蛋白来准确预测哪些患者将被分类为微量白蛋白尿或正常白蛋白尿的能力。我们分析了来自糖尿病患者的总共2904份尿液样本的研究数据。这些数据来自我们自己的研究（190份样本）和一组选定的10篇出版物。尿液中白蛋白的标准实验室测量结果用作“金标准”。根据汇总数据计算的敏感性和特异性分别为83.2%和92.3%。预测值是使用微量白蛋白尿（MAU）患病率的模拟变化计算的。在MAU患病率为1%时，阴性检测的预测值为99.9%，而阳性检测的预测值仅为9.8%。在MAU患病率为80%时，阳性预测值为97.7%，阴性预测值为57.9%。一般来说，患病率的任何变化都会导致预测值的变化。因此，在给定临床环境中MAU的患病率是决定MICRAL检测效用的决定性因素。
