The effect of surgical site infection on older operative patients

Abstract

Objectives: To determine the effect of surgical site infection (SSI) on mortality, duration of hospitalization, and hospital cost in older operative patients.

Design: Retrospective matched-outcomes study.

Setting: Eight hospitals, including Duke University Medical Center, and seven community hospitals.

Participants: Patients aged 65 and older undergoing surgery from 1991 to 2003. Cases were defined as patients who developed deep incisional or organ or space SSI; controls were operative patients who did not develop SSI. Controls were frequency matched to cases according to type and year of operative procedure and to hospital in a 1:1 ratio.

Measurements: Mortality, duration of hospitalization (including re-admissions), and hospital charges for the 90 days after surgery.

Results: One thousand three hundred thirty-seven patients were enrolled in the study: 561 cases with SSI and 576 controls without SSI. In cases, the most common SSI pathogen was Staphylococcus aureus (n=275, 51.6%). Of S. aureus isolates, 58.2% were methicillin resistant. One hundred sixteen subjects died within 90 days of surgery (8.6%). In multivariable analysis, SSI was associated with greater mortality risk (odds ratio (OR)=3.51, 95% confidence interval (CI)=2.20-5.59), 2.9 times longer postoperative hospitalization (95% CI=2.61-3.13), and 1.9 times greater hospital charges (95% CI=1.78-2.10).

Conclusion: In elderly operative patients, SSI was associated with almost 4 times greater mortality, a mean attributable duration of hospitalization after surgery of 15.7 days (95% CI=13.9-17.6) and mean attributable hospital charges of $43,970 (95% CI=$31,881-56,060).