- Oral presentation
- Open Access
The cost bloodstream infections caused by antimicrobial susceptible and non-susceptible Enterobacteriaceae and Staphylococcus aureus in European hospitals
© Stewardson et al; licensee BioMed Central Ltd. 2015
Published: 16 June 2015
Antimicrobial resistance (AMR) represents a significant global threat. It is useful to estimate the economic burden of AMR as these represent potential cost savings from reducing the problem.
To determine the impact of antimicrobial resistance on cost attributable to bloodstream infections (BSIs) caused by Staphylococcus aureus and Enterobacteriaceae from a European hospital perspective.
We performed a multicentre retrospective cohort study including acute inpatient episodes at ten European hospitals in 2010 and 2011. BSIs were the time-varying exposure of interest, with S. aureus classified as methicillin-susceptible (MSSA) or resistant (MRSA), and Enterobacteriaceae as third-generation-cephalosporin-susceptible (3GCSE) or resistant (3GCRE). We used multistate models to estimate excess length-of-stay (LOS). For each bacteria/susceptibility combination, we computed the attributable cost of a single BSI as the product of excess LOS and the bed-day value. We used two contrasting bed-day values: an economic value obtained by contingent valuation and the accounting cost derived by dividing the annual hospital budget by the number of bed-days. To estimate the annual hospital costs of each BSI, these BSI costs were multiplied by the expected number of BSI cases per year. We performed a probabilistic sensitivity analysis to account for parameter uncertainty.
Our cohort included 606,649 patients. Third-generation-cephalosporin-resistance significantly increased the hazard of death (1.5 [1.0–2.2]), excess LOS (4.9 [1.1–8.7]) and cost compared to susceptible strains, whereas methicillin resistance did not. Whilst 3GCSE BSI was associated with the lowest per-infection cost (€320 [95% credible interval, €80–€1,300] or €4,000 [€2,400–€6,700] using economic and accounting valuations, respectively), their relative frequency resulted in equal highest annual cost with MSSA (€77,000 [€19,000–€300,000] or €970,000 [€590,000–€1,600,000] using economic and accounting valuations, respectively).
While BSI with S. aureus has a greater impact on mortality, excess LOS and cost than Enterobacteriaceae per infection, the impact of antimicrobial resistance is greater amongst BSIs caused by Enterobacteriaceae.
Disclosure of interest
This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.