BACKGROUND Delayed diagnosis of bloodstream infection (BSI) occurs in > 20% of older patients, with misdiagnosis in 35%. Our objective was to develop and validate a clinically useful screening tool to identify older patients with a high probability of having a BSI. METHODS Hospitalized patients > 80 years old with BSI (n = 105/group) were evaluated for the tool development in this retrospective matched case-controlled study (learn cohort). The tool was validated in different retrospectively matched case and control patients > 80 years old (n = 120/group) and 65 to 79 years old (n = 250/group) (test cohort). Binary logistic regression was used to develop a screening tool using laboratory and clinical parameters that were significantly associated with BSI (P < 0.05; adjusted odds ratio (OR) > 1); and Classification and Regression Tree (CART) analysis was used to identify parameter breakpoints. Performance metrics were used to evaluate and validate the tool. RESULTS The significant parameters associated with BSI were maximum temperature (Tmax)(> 37.55C)(OR = 42.575), neutrophils (> 7.95)(OR = 1.923), a change in level of consciousness (LOC) (Yes = 1, No = 0)(OR = 1.571), blood urea nitrogen (BUN)(> 10.05)(OR = 1.359), glucose (> 7.35)(OR = 1.167), albumin (< 33.5)(OR = 1.038) and alanine aminotransferase (ALT) (> 19.5)(OR = 1.005). The optimal screening tool [Ln (odds of BSI) = - 150.299 + 3.751(Tmax) + 0.654(neutrophils) + 0.452(change in LOC) + 0.307(BUN) + 0.154(glucose) + 0.038(albumin) + 0.005(ALT)] had favorable performance metrics in the learn and test cohorts (sensitivity, specificity and accuracy of 95% in the learn cohort and 77, 89, and 81% in the total test cohort); and performed better than using only temperature and neutrophil count. CONCLUSIONS The validated tool had high predictive value which may improve early identification and management of BSI in older patients.

中文翻译：

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一项回顾性病例对照研究，开发和验证了一种筛查工具，用于早期识别老年患者的血流感染。

背景技术血流感染（BSI）的延迟诊断发生在20％以上的老年患者中，其中35％的诊断错误。我们的目标是开发和验证一种临床上有用的筛查工具，以识别出具有高BSI可能性的老年患者。方法在这项回顾性匹配病例对照研究（学习队列）中，对住院> BSI的80岁以上患者（n = 105 /组）进行了工具开发评估。该工具已在年龄大于80岁（n = 120 /组）和65至79岁（n = 250 / group）的不同回顾性病例和对照患者中进行了验证（测试队列）。二元逻辑回归用于开发筛选工具，该工具使用与BSI显着相关的实验室和临床参数（P <0.05；调整后的优势比（OR）> 1）；分类和回归树（CART）分析用于确定参数断点。性能指标用于评估和验证工具。结果与BSI相关的重要参数是最高温度（Tmax）（> 37.55C）（OR = 42.575），中性粒细胞（> 7.95）（OR = 1.923），意识水平（LOC）的变化（是= 1，否= 0）（OR = 1.571），血液尿素氮（BUN）（> 10.05）（OR = 1.359），葡萄糖（> 7.35）（OR = 1.167），白蛋白（<33.5）（OR = 1.038）和丙氨酸氨基转移酶（ ALT）（> 19.5）（或= 1.005）。最佳筛选工具[Ln（BSI的几率）=-150.299 + 3.751（Tmax）+ 0.654（中性粒细胞）+ 0.452（LOC变化）+ 0.307（BUN）+ 0.154（葡萄糖）+ 0.038（白蛋白）+ 0.005（ALT） ）]在学习和测试队列中具有良好的绩效指标（敏感性，学习队列的特异性和准确性分别为95％和总测试队列的77％，89和81％）；与仅使用温度和嗜中性粒细胞计数相比，效果更好。结论经过验证的工具具有较高的预测价值，可改善老年患者BSI的早期识别和管理。