Prediction of mortality in Staphylococcus aureus bloodstream infection using quick Pitt bacteremia score.

ABSTRACT

OBJECTIVES: The quick Pitt bacteremia score (qPitt) predicts mortality in patients with serious infections due to gram-negative bacteria. This retrospective cohort study examines utility of qPitt to predict mortality in patients with Staphylococcus aureus bloodstream infection (SAB). METHODS: Multivariate logistic regression was used to examine risk factors for 28-day mortality in hospitalized adults with SAB at four Prisma Health hospitals in South Carolina, USA from January 2015 to December 2017. Area under receiver operating characteristic curve (AUROC) was used to examine model discrimination. RESULTS: Among 692 patients with SAB, 305 (44%) had methicillin-resistant S. aureus (MRSA), and 129 (19%) died within 28 days. After adjustment for age, comorbidities, and MRSA, each component of the qPitt was associated with 28-day mortality. There was a 3-fold increase in the risk of 28-day mortality for each one-point increase in qPitt. Predicted 28-day mortality was 3%, 9%, 22%, 45%, and 70% for qPitt of 0, 1, 2, 3, and ≥4, respectively. AUROC of the qPitt in predicting 28-day, 14-day, and in-hospital mortality were 0.80, 0.81, and 0.80, respectively. CONCLUSIONS: The qPitt predicts mortality with good discrimination in SAB. These results support using qPitt as a measure of acute severity of illness in future studies.