Table1_Risk factors associated with inappropriate empirical antimicrobial treatment in bloodstream infections. A cohort study.XLS

Introduction: Bloodstream infections (BSI) are a major cause of mortality all over the world. Inappropriate empirical antimicrobial treatment (i-EAT) impact on mortality has been largely reported. However, information on related factors for the election of i-EAT in the treatment of BSI in adults is lacking. The aim of the study was the identification of risk-factors associated with the use of i-EAT in BSI.
Methods: A retrospective, observational cohort study, from a prospective database was conducted in a 400-bed acute-care teaching hospital including all BSI episodes in adult patients between January and December 2018. The main outcome variable was EAT appropriation. Multivariate analysis using logistic regression was performed.
Results: 599 BSI episodes were included, 162 (24%) received i-EAT. Male gender, nosocomial and healthcare-associated acquisition of infection, a high Charlson Comorbidity Index (CCI) score and the isolation of multidrug resistant (MDR) microorganisms were more frequent in the i-EAT group. Adequation to local guidelines’ recommendations on EAT resulted in 91% of appropriate empirical antimicrobial treatment (a-EAT). Patients receiving i-EAT presented higher mortality rates at day 14 and 30 when compared to patients with a-EAT (14% vs. 6%, p = 0.002 and 22% vs. 9%, p < 0.001 respectively). In the multivariate analysis, a CCI score ≥3 (OR 1.90 (95% CI 1.16–3.12) p = 0.01) and the isolation of a multidrug resistant (MDR) microorganism (OR 3.79 (95% CI 2.28–6.30), p < 0.001) were found as independent risk factors for i-EAT. In contrast, female gender (OR 0.59 (95% CI 0.35–0.98), p = 0.04), a correct identification of clinical syndrome prior to antibiotics administration (OR 0.26 (95% CI 0.16–0.44), p < 0.001) and adherence to local guidelines (OR 0.22 (95% CI 0.13–0.38), p < 0.001) were identified as protective factors against i-EAT.
Conclusion: One quarter of BSI episodes received i-EAT. Some of the i-EAT related factors were unmodifiable (male gender, CCI score ≥3 and isolation of a MDR microorganism) but others (incorrect identification of clinical syndrome before starting EAT or the use of local guidelines for EAT) could be addressed to optimize the use of antimicrobials.

引言：血流感染（Bloodstream Infections, BSI）是全球范围内导致患者死亡的主要病因之一。不恰当的经验性抗菌治疗（inappropriate empirical antimicrobial treatment, i-EAT）对病死率的影响已有大量研究报道。然而，目前尚缺乏成人血流感染治疗中选择不恰当经验性抗菌治疗的相关影响因素的研究数据。本研究旨在明确成人血流感染患者使用不恰当经验性抗菌治疗的相关危险因素。

方法：本研究依托一项前瞻性数据库，于一家拥有400张床位的教学型急症医院开展，为回顾性观察队列研究，纳入2018年1月至12月期间所有成人患者的血流感染发作病例。本研究的主要结局变量为经验性抗菌治疗（empirical antimicrobial treatment, EAT）的恰当性，并采用logistic回归进行多因素分析。

结果：本研究共纳入599例血流感染发作病例，其中162例（24%）接受了不恰当经验性抗菌治疗。在不恰当经验性抗菌治疗组中，男性、医院获得性感染与医疗相关感染、较高的查尔森合并症指数（Charlson Comorbidity Index, CCI）得分以及分离出多重耐药（multidrug resistant, MDR）微生物的比例更高。遵循当地经验性抗菌治疗指南推荐的患者中，91%接受了恰当经验性抗菌治疗（appropriate empirical antimicrobial treatment, a-EAT）。与恰当经验性抗菌治疗组患者相比，接受不恰当经验性抗菌治疗的患者在感染后14天和30天的病死率更高（分别为14% vs. 6%，p=0.002；22% vs. 9%，p<0.001）。多因素分析结果显示，查尔森合并症指数得分≥3（优势比OR=1.90，95%置信区间CI=1.16~3.12，p=0.01）以及分离出多重耐药微生物（OR=3.79，95%CI=2.28~6.30，p<0.001）是不恰当经验性抗菌治疗的独立危险因素。与之相反，女性性别（OR=0.59，95%CI=0.35~0.98，p=0.04）、抗菌药物使用前正确识别临床综合征（OR=0.26，95%CI=0.16~0.44，p<0.001）以及遵循当地指南（OR=0.22，95%CI=0.13~0.38，p<0.001）被确定为不恰当经验性抗菌治疗的保护因素。

结论：四分之一的血流感染发作病例接受了不恰当经验性抗菌治疗。部分与不恰当经验性抗菌治疗相关的因素为不可干预因素（如男性性别、查尔森合并症指数得分≥3以及分离出多重耐药微生物），而其余因素（如抗菌治疗开始前未正确识别临床综合征或未遵循当地抗菌治疗指南）可通过干预措施优化抗菌药物的临床使用。