Derivation of a clinical prediction rule for bloodstream infection mortality of patients visiting the emergency department based on predisposition, infection, response, and organ dysfunction concept

Background/Purpose Bloodstream infection (BSI) is a serious infection with a high mortality. We aimed to construct a predictive scoring system to stratify the severity of patients with BSI visiting the emergency department (ED). Methods We conducted a retrospective cohort study consisting of patients who visited the ED of a tertiary hospital with documented BSI in 2010. The potential predictors of mortality were obtained via chart review. Multivariate logistic regression was utilized to identify predictors of mortality. Penalized maximum likelihood estimation (PMLE) was applied for score development. Results There were 1063 patients with bacteremia included, with an overall 28-day mortality rate of 13.2% ( n  = 140). In multiple logistic regression with penalization, the independent predictors of death were "predisposition": malignancy (β-coefficient, 0.65; +2 points); "infection": Staphylococcus aureus ( S. aureus ) bacteremia (0.69; +2 points), pneumonia (1.32; +4 points), and bacteremia with an unknown focus (0.70; +2 points); "response": body temperature 5% (1.00; +3 points), and red blood cell distribution width (RDW) >15% (0.63; +2 points); and "organ dysfunction": pulse oximeter oxygen saturation 2 mg/dL (0.69; +2 points). The area under receiver operating characteristic curve (AUROC) for the model was 0.881 [95% confidence interval (CI), 0.848–0.913], with a better performance than the Pitt bacteremia score (AUROC: 0.750; 95% CI 0.699–0.800, p Conclusion The new scoring system for bacteremia could facilitate the prediction of the risk of 28-day mortality for patients visiting the ED with BSI.