Incremental Clinical and Economic Burden of Suspected Respiratory Infections due to Multidrug-Resistant Pseudomonas aeruginosa in the United States.

BACKGROUND: Multidrug resistant (MDR) Pseudomonas aeruginosa can negatively affect patients and hospitals.

AIM: To evaluate excess mortality and cost burden among patients hospitalized with suspected respiratory infections due to MDR P. aeruginosa versus patients with non-MDR P. aeruginosa in 78 United States (US) hospitals.

METHODS: We analyzed electronically captured microbiological and outcomes data of patients hospitalized with nonduplicate P. aeruginosa isolates from respiratory source collected ≥3 days after admission to identify hospital-onset MDR or non-MDR P. aeruginosa per the Centers for Disease Control and Prevention definition. We estimated the risk of multidrug resistance on mortality, length of stay (LOS), cost, operation gain/loss, and 30-day readmission. We conducted a sensitivity analysis utilizing a cohort with pharmacy data available.

FINDINGS: Of 523 MDR and 1381 non-MDR P. aeruginosa cases, unadjusted mortality was 23.7% versus 18.0% and multivariable-adjusted mortality was 20.0% (95% confidence interval [CI]: 14.3%-27.2%) versus 15.5% (95% CI: 11.2%-20.9%; P=0.026), the average adjusted excess LOS was 6.7 days (P<0.001); excess cost per case was US$22 370 higher (P=0.002) and operational loss per case was US$10 661 (P=0.024) greater, and the multivariable adjusted readmission rate was 16.2% (95% CI: 11.2%-22.9%) versus 11.1% (95% CI: 7.8%-15.6%; P=0.006). The sensitivity analysis yielded similar results.

CONCLUSIONS: Compared with suspected infections due to non-MDR P. aeruginosa, patients with MDR P. aeruginosa had higher risk of mortality, readmission, and longer LOS, as well as US$20 000 incremental cost and >US$10 000 incremental net loss per case after controlling for patient and hospital characteristics.