Dyerberg J, Pedersen L, Aagaard O
Clin Chem. 1976 Feb;22(2):205-10.
As an example of qualitative tests, a dipstick analysis for glucose in urine has been tested for the influence of modifying factors on the test result. Two different types of dipsticks were examined, "Clinistix" and "S-Gluko-test." Used according to manufacturer's instructions, the latter is more sensitive and selective. By multivariance analysis the following variables were examined: urine samples, inter- and intra-analyst, exposure to light, and dipstick batch. The first three contributed significantly to the total variation in results, inter-specimen variation being the most important. With knowledge of the frequency of testing urines with a given glucose concentration and the probability of the result at that concentration, an expression of the probability of the glucose content of a urine sample can be obtained. Even with the tests of the type examined having a sensitivity and specificity exceeding 95%, 14 of 100 patients suspected of having diabetes mellitus on the basis of a dipstick examination will be found to have a urinary glucose concentration of less than 2 mmol/liter. These figures were found when the prevalence of urines with a glucose concentration exceeding 2 mmol/liter was 17.5%.
作为定性检测的一个例子，已对用于检测尿糖的试纸分析进行了测试，以考察各种影响因素对检测结果的作用。对两种不同类型的试纸“Clinistix”和“S - 葡萄糖检测试纸”进行了检查。按照制造商的说明使用时，后者更灵敏且更具选择性。通过多变量分析，对以下变量进行了考察：尿样、分析人员之间和分析人员内部、光照以及试纸批次。前三个因素对结果的总变异有显著影响，其中样本间变异最为重要。了解具有给定葡萄糖浓度的尿液检测频率以及该浓度下结果出现的概率，就可以得出尿样中葡萄糖含量的概率表达式。即使所检测的这类检测的灵敏度和特异性超过95%，在基于试纸检查疑似患有糖尿病的100名患者中，仍会发现有14名患者的尿糖浓度低于2毫摩尔/升。这些数据是在葡萄糖浓度超过2毫摩尔/升的尿液患病率为17.5%时得出的。
