All-cause and infection-attributable mortality amongst adults with bloodstream infection – a population-based study

Abstract

AbstractBackgroundBloodstream infections (BSI), are common, life threatening infections. However, it remains unclear whether deaths following BSI are primarily due to uncontrolled infection or underlying comorbidities. We aimed to determine the overall mortality, infection-attributable mortality, and causes of death for four leading BSI pathogens.MethodsThis retrospective cohort study was conducted within the SAIL Databank, containing anonymised population-scale electronic health record data for Wales, UK. We included adults withEscherichia coli, Klebsiella sp, Pseudomonas aeruginosaandStaphylococcus aureusBSI between 2010-2022 using linked data from Public Health Wales and the Office for National Statistics. 30-day all-cause and sepsis-specific mortality, as a proxy for infection-attributable mortality, were compared using Cox proportional hazards and competing risk regression respectively.FindingsWe identified 35,691 adults with BSI.E. coliwas the most prevalent (59.6%). Adjusted analyses revealed that all organisms had a higher 30-day mortality vs.E. coliwith MRSA the highest (HR: 2.04 [1.83-2.37], p<0.001).Cancer was the leading cause of death following BSI for all organisms, particularly deaths occurring between 30-90 days (35.9%). 25.5% of deaths within 30 days involved sepsis. MRSA was associated with the highest sepsis mortality vs.E. coli(HR: 2.45 [2.12-2.82], p<0.001). Peak CRP was positively associated with increased sepsis mortality (p<0.001).InterpretationThis population-level study challenges the assumption that most deaths following BSI are directly attributable to uncontrolled infection. Our findings underscore the need for re-evaluating clinical trial design and developing better preventative strategies for BSI.FundingThis work is funded by the Medical Research Council [grant number MR/T023791/1].