应用受试者工作特征曲线探讨UF-1000i尿沉渣分析仪在快速筛检泌尿系统感染中的应用

目的 应用受试者工作特征（ROC）曲线探讨UF-1000i尿沉渣分析仪定量检测尿沉渣白细胞（WBC）和细菌计数作为快速筛检泌尿系统感染指标的可行性。 方法 2013年8月－12月分别用定量细菌培养法和UF-1000i自动尿沉渣分析仪检测218例疑似泌尿系统感染患者清洁中段尿标本。 结果 218例尿沉渣标本中尿液细菌培养阳性标本为65例，以尿培养阳性为金标准制作ROC曲线，UF-1000i尿沉渣分析仪检测WBC和细菌计数的ROC曲线下面积分别为0.839和0.894；最佳约登指数的WBC和细菌计数的临界值分别为≥31.0/μL和≥38.8/μL。以此为临界值其WBC计数的灵敏度和特异度分别为78.3%和80.4%，阳性似然比为3.99，阴性似然比为1.11；细菌计数的灵敏度和特异度分别为84.3%和80.6%，阳性似然比为4.30，阴性似然比为0.80。 结论 以UF-1000i尿沉渣分析仪检测白细胞计数≥31.0/μL和细菌计数≥38.8 /μL为临界值作为无创性检测指标，在早期筛检泌尿系统感染，判断是否需要进行尿液培养，以及指导临床合理应用抗生素等方面具有重要应用价值。

Research on the Application of UF-1000i Urine Sediment Analyzer in Rapid Urinary Tract Infection Screening by Receiver Operator Characteristic Curve

Objective To investigate the feasibility of quantitative detection of WBC count and bacteria count with UF-1000i urinary sediment analyzer in rapid screening for urinary tract infection by receiver operator characteristic （ROC） curve. Methods From August to December 2013, we used quantitative bacterial culture and UF-1000i automatic urine sediment analyzer respectively to examine asepsis urine specimens of 218 patients with suspected urinary tract infection. Among them, there were 95 males and 123 females, with an average age of 54.7 years old. Results Among the 218 urinary samples, 65 were culture positive specimens. With positive urine culture as the gold standard for making ROC curve, the area under ROC curve for WBC count and bacterial numbers by UF-1000i urine sediment analyzer were respectively 0.839 and 0.894. The cut-off values of Youden index for optimal WBC cell count and bacterial count were≥ 31.0/μL and 38.8/μL, respectively. When the above numbers were used as cut-off values, the WBC count sensitivity and specificity were 78.3% and 80.4%, the positive likelihood ratio was 3.99, and the negative likelihood ratio was 1.11. And the bacterial count sensitivity and specificity were 84.3% and 80.6%, the positive likelihood ratio was 4.30, and the negative likelihood ratio was 0.80. Conclusion Using white blood cell count ≥ 31/μL and bacterial count ≥ 38.8/μL detected by UF-1000i urine sediment analyzer as the cut off values of noninvasive screening indexes has a very important value in screening for urinary tract infection in the early stage, determining whether there is a need for urine culture, and guiding clinical rational application of antibiotics.