Economic Analysis of the European Healthcare Burden of Sternal-Wound Infections Following Coronary Artery Bypass Graft

Abstract

Background: Sternal wound infections (SWIs) can be some of the most complex surgical-site infections (SSIs) and pose a considerable risk following coronary artery bypass graft surgery (CABG). Objective: To capture the cost burden of SWIs following CABG across European countries. Methods: We modeled a standardized care pathway for CABG, starting at the point of surgery and extending to 1-year post surgery. The Markov model captures the incidence and cost of an SWI (deep or superficial SWIs). The cost burden is calculated from a hospital perspective such that the main inputs relating to costs were intensive-care-unit (ICU) and general-ward (GW) days. Outpatient care, not in the hospital setting, has no cost in this analysis. Model input parameters were taken from Eurostat and a review of published, peer-reviewed literature. European countries were included in this analysis when values for 50% of the required input parameters per country were identified. Missing data points were interpolated from available data. The robustness of results was assessed via probabilistic sensitivity analysis. Results: Full required input data were available for 8 European countries; a further 18 countries had sufficient data for analysis. The median (interquartile range) for SWI incidence across the 26 countries was 3.9% (2.9-5.6%). The total burden for all 26 countries of SWIs after CABG was €170.8 million. These costs were made up of 25,751 additional ICU days, 137,588 additional GW days, and 7,704 readmissions. The mean cost of an SWI ranged from €8,924 in Poland to €21,321 in Denmark. Relative to the costs of post-CABG care without an SWI complication, the incremental cost of an SWI was highest in Greece (24.9% increase) and lowest in the UK (3.8% increase) with a median (interquartile range) of 12% (10-16%) across all 26 countries. Conclusions: SWIs following CABG present a considerable burden to healthcare budgets.

Keywords: Europe; healthcare costs; hospital costs; length of stay; surgical wound infection.

Figure 1

(A) State transitions in the Markov model. (B) Example of model inputs for the UK. CABG, coronary artery bypass graft; ICU, intensive care unit; GW, general ward; MV, mechanical ventilation; SWI, sternal wound infection; DSWI, deep SWI; SSWI, superficial SWI.

Figure 2

Black: full data available. Dark gray: ≥5 parameters available. Light gray: insufficient data available. White: not investigated.

Figure 3

Data for the Netherlands is not depicted as this was the only country not reporting data at 30 days. The overall incidence of sternal wound infections is shown in black text above each bar, in white text are the values for DSWI (black bars), and superficial sternal wound infections (SSWI, gray bars). SWI, sternal wound infection; DSWI, deep SWI; SSWI, superficial SWI.

Figure 4

This figure contains data for the eight countries with a full set of parameters and the combined data for all countries included in the analysis (under Europe). Values represent the relative increase of CABG care costs due to SWIs. CABG, coronary artery bypass graft; SWI, sternal wound infection.

Figure 5

Box and whisker chart showing the median and interquartile range (IQR, central box), the mean (cross x). Each whisker extends 1.5x the IQR, points beyond this are considered outliers. CABG, coronary artery bypass graft; SWI, sternal wound infection.