Eurosurveillance have recently published a study from the TIMER group evaluating the impact of antimicrobial resistance on hospital mortality, excess length of stay (LOS), and cost of BSI in European hospitals. The study highlights the high cost of BSIs, especially when antimicrobial resistant.
The study is vast, including more than 600,000 patients from 10 hospitals in Europe. The outcomes centred around 3rd generation cephalosporin resistant Enterobacteriaceae (3GCRE – not certain that this acronym will catch on…) and MRSA. There are some important messages in the study around the relative impact of antimicrobial resistance in Enterobacteriaceae vs. S. aureus (see Table 1 below). (If there are any authors reading, I am conscious that this is a ‘tabloid’ simplification of elegantly calculated estimates, carefully adjusted for a range of possible confounders!) It was interesting that whilst methicillin-resistance in S. aureus did not significantly increase mortality, extend LOS, or increase cost, 3rd generation cephalosporin resistance in Enterobacteriaceae did increase all three measures.
| Organism | Daily risk of hospital death (hazard ratio) | Prolonged LOS (days) | Cost per case (Euros) |
| 3GCSE | NS | 5.9 | 320 |
| 3GCRE | 1.8 | 9.3 | 560 |
| MSSA | 1.8 | 11.5 | 760 |
| MRSA | 2.4 | 13.3 | 890 |
Table 1: Summary of key outcomes by organism group. NS = not significant.
The authors also looked at the prevalence of the various groups, and the likely cost to the hospitals over a year (Figure 1). Although MRSA was most expensive on a per-case basis, it was the least expensive to a hospital over a year because of its low prevalence. Interestingly, the susceptible groups (MSSA and 3GCSE) were the most expensive to the hospital over the course of a year. And yet how much focus do we place on susceptible BSIs? Not nearly enough!
Figure 1: The expected cost per hospital year of antimicrobial susceptible and resistant BSI.
The data are from 2010-2011, which is now half a decade ago. Much has changed in that time in terms of the rate of antimicrobial resistance – methicillin-resistance is less common in some parts of Europe, whereas 3GCR is more common throughout. In many areas of Europe, this study suggests that the money is telling us to shift our prevention activities away from antimicrobial resistant versions of key pathogens and towards expensive manifestations of key pathogens, regardless of their antimicrobial resistance status.
Image: Flickr.
Reflections on Infection Prevention and Control 