Background. The balance between the choices of UTI diagnostic tools in most primary care settings has been settled for by the more rapid, less labour-intensive dipstick. This study aimed to evaluate the effectiveness of dipstick for diagnosing UTI. Method. A total of 429 urine samples were collected from patients suspected of UTI; cultured on cysteine-lactose-electrolyte-deficient (CLED) agar, blood agar, and MacConkey agar; and incubated at 37°C overnight. Urine cultures with bacteria count ≥10⁵ cfu/ml were classified as “positive” for UTI. A dipstick was used to screen for the production of nitrite (NIT) and leucocyte esterase (LE), following the manufacturer’s instructions. Biochemical reactions of nitrite and leucocyte esterase > “trace” were classified as “positive.” A quantitative urine culture was used as the gold standard. Results. The highest sensitivity value and negative predictive value were recorded for the combined “NIT+ or LE+” dipstick results. The highest specificity value, positive predictive value, positive likelihood ratio, and negative likelihood ratio were recorded for “nitrite-positive and leucocyte esterase-positive” results. Combined “nitrite-positive or leucocyte-positive” result was relatively the best indicator for accurate dipstick diagnosis, with AUC = 0.7242. Cohen’s kappa values between dipstick diagnosis and quantitative culture were <0.6. Conclusion. Combined performance of nitrite and leucocyte esterase results appeared better than the solo performance of nitrite and leucocyte esterase. However, little confidence should be placed on dipstick diagnosis; hence, request for quantity culture should be encouraged in the primary healthcare settings.

中文翻译：

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试纸检测尿路感染的有效性。

背景。在大多数初级保健机构中，UTI 诊断工具的选择之间的平衡已经通过更快速、劳动强度更低的量油尺来解决。本研究旨在评估试纸诊断 UTI 的有效性。方法。从疑似UTI的患者中收集了429份尿液样本；在半胱氨酸-乳糖-电解质缺乏 (CLED) 琼脂、血琼脂和麦康凯琼脂上培养；并在 37°C 下孵育过夜。细菌计数≥10 ^{5的尿液培养物} cfu/ml 被归类为 UTI 的“阳性”。按照制造商的说明，使用试纸筛选亚硝酸盐 (NIT) 和白细胞酯酶 (LE) 的产生。亚硝酸盐和白细胞酯酶的生化反应>“微量”被归类为“阳性”。定量尿培养被用作金标准。结果. 对于组合的“NIT+ 或 LE+”量油尺结果，记录了最高灵敏度值和阴性预测值。记录“亚硝酸盐阳性和白细胞酯酶阳性”结果的最高特异性值、阳性预测值、阳性似然比和阴性似然比。结合“亚硝酸盐阳性或白细胞阳性”结果是准确试纸诊断的最佳指标，AUC = 0.7242。试纸诊断和定量培养之间的 Cohen's kappa 值 <0.6。结论. 亚硝酸盐和白细胞酯酶的联合表现似乎优于亚硝酸盐和白细胞酯酶的单独表现。然而，对试纸诊断应该没有什么信心。因此，应鼓励在初级保健机构中要求数量培养。