Risk factors for long-term mortality of Staphylococcus aureus bacteremia

Abstract

Staphylococcus aureus bacteremia (SAB) is a fatal disease. We aimed to describe risk factors for long-term mortality with SAB. We analyzed data from a retrospectively collected database including 1,692 patients with SAB. We considered variables of infection and background conditions for the analysis of long-term survival. The Kaplan-Meier procedure was used for analysis of long-term survival. Variables significantly associated with mortality were analyzed using a Cox regression model. We included 1,692 patients in the analysis. Patients were followed for up to 22 years. Within one year, 62% of patients died and within 5 years 72% died. A total of 82% of patients aged 65 years and older died within 5 years. Independent predictors of long-term mortality were older age (Hazard ratio 1.029, 95% confidence interval 1.022-1.036), female gender (HR 1.302, 95% CI 1.118-1.517), pneumonia or primary/ unknown source of infection (HR 1.441, 95% CI 1.230-1.689), dementia (HR 1.234, 95% CI 1.004-1.516), higher Charlson score (HR 1.155, 95% CI 1.115-1.196), shock at onset (HR 1.776, 95% CI 1.430-2.207) and arrival to hospitalization from an institution (HR 1.319, 95% CI 1.095-1.563). Long-term survival of patients older than 65 years and of women with SAB is severely curtailed.