A benchmarking study of thirty-day mortality following Staphylococcus aureus or Escherichia coli bacteremia

Abstract

Objectives: To compare the case-fatality rate (CFR) following bacteremia caused by Staphylococcus aureus or Escherichia coli between acute care hospitals in Israel, Israel and estimates from published meta-analyses, and Israel and England.

Methods: This epidemiologic assessment used nationwide data from Israel and England and meta-analyses. We included all patients with S. aureus or E. coli bacteremia in 2018-2019. The outcome was the case-fatality rate, defined as 30-day all-cause mortality.

Results: Crude CFR varied widely between Israeli hospitals, ranging from 20.0% to 45.0% for methicillin-susceptible S. aureus (MSSA), 22.9-66.7% for methicillin-resistant S. aureus (MRSA), 0.0-21.8% for third-generation cephalosporin-susceptible (3GC-S) E. coli, and 17.5-36.6% for third-generation cephalosporin-resistant (3GC-R) E. coli. Age-adjusted CFRs in Israel were significantly higher than in England: risk differences were 6.4% (95% CI: 5.2-7.6%) for MSSA, 13.0% (95% CI: 7.5%-18.5%) for MRSA, 1.4% (95% CI: 0.7-2.0%) for 3GC-S E. coli, and 8.8% (95% CI: 6.9-10.8%) for 3GC-R E. coli. CFRs in Israel were higher than in meta-analyses, although confidence intervals overlapped for E. coli.

Conclusions: Three determinants could explain elevated CFR following bacteremia: host factors, bacterial factors, and timeliness and appropriateness of treatment. The latter are modifiable. Benchmarking could direct improvement efforts that save lives.

Keywords: Bacteremia; Benchmarking; Case-fatality rate; Escherichia coli; Staphylococcus aureus.