Economic aspects of deep sternal wound infections

Surgical-site infections are a very expensive complication in cardiac surgery. Thus, the total costs for coronary artery bypass grafting (CABG) surgery may substantially increase when a deep sternal wound infection (DSWI) occurs. This may be due to an extended length of stay (LOS), the need for additional surgical procedures, vacuum-assisted wound dressing and antibiotic therapy. This study compares the LOS in the hospital and on an intensive care unit (ICU) as well as the total costs for patients undergoing CABG depending upon the occurrence of a subsequent DSWI.

A case-control study was performed. Total costs of DSWI cases were analysed and compared to patients undergoing CABG without DSWI. Inclusion criterion for cases was the development of a DSWI according to the CDC criteria during hospital stay after CABG. Two control patients without any signs or symptoms of an infection during hospital stay were matched to each case by (1) type of surgery according to their diagnosis-related group (DRG), (2) age +/-5 years, (3) gender and (4) duration of preoperative hospital stay +/-2 days, but at least as long as the time at risk of cases before infection.

Between January 2006 and March 2008, 17 CABG patients with DSWI (cases) and 34 matched controls were included. The median overall costs of a CABG case were 36,261 Euro compared with 13,356 Euro per control patient without infection (p<0.0001). The median overall LOS was 34.4 days versus 16.5 days, respectively (p=0.0006). The median LOS on ICU was 6.3 days versus 5.3 days (no significant difference).

DSWI represents an important economic factor for the hospital as they may almost triple the costs for patients undergoing CABG. Thus, appropriate infection control measures for the prevention of DSWI should be enforced.