Background: The clinical and economic impact of bloodstream infections (BSI) due to multi-drug resistant (MDR) Gram negative bacteria (GNB) are incompletely understood.
Methods: From 2004-2015, all adult inpatients with GNB BSI at Duke Hospital were prospectively enrolled. MDR was defined as resistant to ≥3 antibiotic classes. Infection route was defined as: 1) hospital-acquired, 2) healthcare-associated, community-acquired, or 3) non-healthcare-associated, community-acquired. Clinical outcomes and inpatient costs associated with MDR status were identified.
Results: 1266 unique patients were enrolled. Of these, 402 (32%) had MDR bacteria. In a multivariable logistic regression, factors associated with MDR infection included history of solid organ or hematological transplant (odds ratio [OR] 1.61; 95% confidence interval [CI] 1.07-2.44; P=0.02) and hospital-acquired infection (OR 1.50; 95% CI 1.13-1.98; P=0.005). Patients with MDR infections were more likely to have longer hospital length of stay [LOS] (Median 11 vs. 8 days; P<0.0001). Unadjusted in-hospital mortality did not significantly differ between the MDR (25.4% [102/402]) and non-MDR (21.3% [184/864]) groups (P=0.10). Unadjusted mean costs were 37% higher in patients with MDR BSI than non-MDR BSI ($156,312 vs. $114,197; P<0.0001), and this persisted after adjustment for patient demographics, APACHE-II scores, infection route, and medical co-morbidities (mean ratio 1.24; 95% CI 1.10- 1.40; P=0.0005) (Figure 1). Statistical significance was not maintained when hospital LOS was added to above covariates (mean ratio 1.06; 95% CI 0.97-1.17; P=0.20). Adjusted analysis of patient sub-populations revealed that the increased cost of MDR infections stemmed from two patient groups: 1) healthcare-associated, community-acquired infections (MDR mean ratio 1.31, 95% CI 1.12-1.54, P=0.0006), and 2) those with severe chronic illnesses (i.e., APACHE-II chronic health score = 5) (MDR mean ratio 1.38, 95% CI 1.20-1.59, P<0.0001).
Conclusion: MDR GNB BSI are associated with longer hospital LOS and increased inpatient costs. MDR infections in chronically ill patients with frequent healthcare contact are driving the increased cost.
J. T. Thaden,
F. Ruffin, Merck: Grant Investigator , Grant recipient
S. Reed, Merck: Grant Investigator , Grant recipient
V. G. Fowler Jr, None
See more of: Poster Abstract Session