Predictors of Healthcare-Associated Bloodstream Infections in Subjects Hospitalised from the Emergency Department for Non-Infectious Disease

Background: Healthcare-associated bloodstream infections (HABSIs) are among the main categories of nosocomial infections. This analysis aims to identify the clinical characteristics of patients in the emergency department (ED) who will develop a HABSI during their hospital stay. Methods: Main outcome measures were HABSI and the cumulative survival rate at 30 days. The features tested in a logistic model were age, sex, vitals by the National Early Warning Score (NEWS), priority levels, main complaints, comorbidities by the Charlson Comorbidity Index (CCI), trauma-related disease, main diagnosis and ED length of stay. Results: In 414 (2.3%) out of 18,304 patients, aged 75 (16) years, mean (SD), a diagnosis of HABSI was recorded. HABSIs occurred in subjects with main diagnosis of diseases of the respiratory system (N = 116; 28.0%), digestive system (N = 72; 17.4%), and circulatory system (N = 68; 16.4%). The main key clinical features selected by the logistic model were: NEWS > 6, diagnosis of neoplasms, CCI > 4, and diagnosis of diseases of the digestive system. The ROC curve for the HABSI risk score was 0.703 ± 0.027 in predicting the outcome, (sensitivity 79%, specificity 51%, at optimal cut-off score). The overall hazard mortality risk was twofold higher in patients with HABSIs (hazard ratio: 2.319; 95% confidence interval: 1.871–2.875; p-value: <0.001). The overall 30-day survival rate was lower among patients with HABSIs (33%) vs. non-HABSI patients (62%). Conclusions: A group of main clinical features in subjects without suspect of infectious disease in the ED are associated with HABSIs. These features negatively impact survival rate during hospital stays.