Validity of Rapid Tests to Detect Nosocomial Urinary Tract Infection in Hospital*

描述(申请人提供)：这项研究的目的是检验白细胞酯酶和亚硝酸盐测试在住院老年人导管相关性尿路感染的护理点检测中的诊断有效性。据估计，40%的住院患者会获得某种类型的医院感染，其中导管相关性尿路感染(CAUTI)是最常见的。根据疾病控制和预防中心最近的一份报告，大约32%的急性护理患者将发生CAUTI。除了限制导尿管的使用外，目前几乎没有证据支持在住院的老年人口中对这种情况进行预防性干预。在测试新的干预措施的有效性之前，研究人员必须首先了解可用的CAUTI方法的诊断有效性，包括快速、廉价和常用的白细胞酯酶和亚硝酸盐测试。研究表明，老年人，特别是那些患有慢性病的人，可能无法对病原体产生有效的免疫反应。这种现象被称为“免疫衰老”，有可能限制白细胞对尿路病原体的反应，表现为“阴性”的白细胞酯酶试验。或者，身体其他部位的活动性急性感染，可能是在医院环境下，可能会提高白细胞的反应，导致住院的老年人口中的白细胞酯酶检测呈“阳性”。目前尚不清楚这两种现象对这一人群中白细胞酯酶试验的总体诊断有效性有什么“净影响”，但拟议的研究将为这一领域的研究提供信息。此外，研究表明，尿路感染的诊断“金标准”--定量尿培养中的尿菌浓度降低，应用于留置导尿管的患者。在这项拟议的研究中，每毫升尿液中1000个(而不是100,000个)细菌的降低浓度将成为白细胞酯酶和亚硝酸盐测试比较的“金标准”。这项横断面研究的三个目的是：1)确定白细胞酯酶试验检测住院老年人CAUTI的敏感性、特异性和阳性预测值；2)确定亚硝酸盐试验检测住院老年人CAUTI的敏感性、特异性和阳性预测值；3)检查联合白细胞酯酶和亚硝酸盐试验检测住院老年人CAUTI的诊断有效性。这项研究有可能消除住院老年人CAUTI的识别和治疗延迟，这可能会预防与高细菌负荷CAUTI相关的并发症，如肾盂肾炎、感染性休克和死亡。

DESCRIPTION (provided by applicant): The purpose of this study is to examine the diagnostic validity of the leukocyte esterase and nitrite tests in the point-of-care detection of catheter-associated urinary tract infection in hospitalized older adults. It is estimated that 40% of all hospitalized patients will acquire some type of nosocomial infection, and catheter-associated urinary tract infection (CAUTI) is the most common. According to a recent report by the Centers for Disease Control and Prevention, approximately 32% of acute care patients will develop a CAUTI. Besides limiting the use of urinary catheters, there is currently very little evidence to support preventitive interventions for this condition in the hospitalized older adult population. Before novel interventions can be tested for efficacy, researchers must first understand the diagnostic validity of available CAUTI measures, including the rapid, inexpensive, and commonly utilized leukocyte esterase and nitrite tests. Research indicates that older adults, particularly those with chronic diseases, may be unable to mount an effective immune response against pathogens. This phenomenon, termed "immunosenescence," has the potential to restrict the white blood cell response to urinary pathogens, reflected by a "negative" leukocyte esterase test. Alternatively, an active, acute infection elsewhere in the body, which is likely in the hospital setting, may elevate the white blood cell response, leading to a "positive" leukocyte esterase test in the hospitalized older adult population. It is not known what "net effect" these two phenomena have on the overall diagnostic validity of the leukocyte esterase test in this population, but the proposed study will inform this area of inquiry. Furthermore, research indicates that a reduced concentration of urinary bacteria in the quantitative urine culture, the diagnostic "gold standard" for UTI, should be used in patients with urinary catheters. This reduced concentration of 1,000 (rather than 100,000) organisms per milliliter of urine will be the "gold standard" against which the leukocyte esterase and nitrite tests will be compared in the proposed study. The three aims for this cross-sectional study are to: 1) Determine the sensitivity, specificity, and positive predictive value of the leukocyte esterase test to detect CAUTI in hospitalized older adults; 2) Determine the sensitivity, specificity, and positive predictive value of the nitrite test to detect CAUTI in hospitalized older adults, and; 3) Examine the diagnostic validity of the combined leukocyte esterase and nitrite tests to detect CAUTI in hospitalized older adults. This research has the potential to eliminate the delay in CAUTI identification and treatment in hospitalized elders, which may prevent the complications associated with high bacterial-load CAUTI, such as pyelonephritis, septic shock, and death.