Background: Proton-pump inhibitors (PPIs) are commonly used in clinical practice for gastric acid suppression. However, these agents have also been associated with certain negative clinical outcomes. We evaluated the real-world effects of incident PPI use on clinical outcomes in patients with Staphylococcus aureus bacteremia.

Methods: This retrospective cohort study included patients admitted to Veterans Affairs hospitals with positive S. aureus blood cultures collected between 2002 and 2013 that received appropriate antibiotics within 48 hours of culture collection. Clinical outcomes among three PPI exposure groups, each compared to nonusers, were assessed with propensity-score-matched Cox proportional-hazard regression models: pretreated PPI users initiating therapy in the 30 days prior to culture and either (a) continuing PPI therapy after culture, or (b) not continuing after culture, and (c) de novo users initiating at culture.

Results: Clinical outcomes, including inpatient mortality, intensive care discharge, 30-day mortality, 30-day readmission, and 30-day Clostridium difficile infection (CDI) were similar among PPI users and nonusers. Though length of stay was longer in pretreated, continuing PPI users [time-to-discharge hazard ratio (HR) 0.78, 95% confidence interval (CI) 0.65–0.93], 14-day mortality was significantly lower than in nonusers (HR 0.66, 95% CI 0.50–0.87).

Conclusions: In our large national cohort study, PPIs were not associated with an increased risk of negative clinical outcomes, including mortality and CDI, in patients with S. aureus bacteremia.