Incremental clinical and economic burden of suspected respiratory infections due to multi-drug-resistant Pseudomonas aeruginosa in the United States.

BACKGROUND: Multi-drug 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 vs patients with non-MDR P. aeruginosa in 78 United States (US) hospitals. METHODS: This study analyzed electronically captured microbiological and outcomes data of patients hospitalized with non-duplicate P. aeruginosa isolates from respiratory sources collected ≥3 days after admission to identify hospital-onset MDR or non-MDR P. aeruginosa per the Centers for Disease Control and Prevention definition. The risk of multi-drug resistance was estimated on mortality, length of stay (LOS), cost, operation gain/loss, and 30-day readmission. A sensitivity analysis was conducted utilizing a cohort with pharmacy data available. FINDINGS: Of 523 MDR and 1381 non-MDR P. aeruginosa cases, unadjusted mortality was 23.7% vs 18.0% and multi-variable-adjusted mortality was 20.0% (95% confidence interval (CI): 14.3-27.2%) vs 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 multi-variable adjusted readmission rate was 16.2% (95% CI: 11.2-22.9%) vs 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.

Attributable clinical and economic burden of carbapenem-non-susceptible Gram-negative infections in patients hospitalized with complicated urinary tract infections.

BACKGROUND: Gram-negative complicated urinary tract infections (cUTIs) can have serious consequences for patients and hospitals. AIM: To examine the clinical and economic burden attributable to Gram-negative carbapenem-non-susceptible (C-NS; resistant/intermediate) infections compared with carbapenem-susceptible (C-S) infections in 78 US hospitals. METHODS: All non-duplicate C-NS and C-S urine source isolates were analysed. A subset had principal diagnosis ICD-9-CM codes denoting cUTI. Collection time (<3 vs ≥3 days after admission) determined isolate classification as community or hospital onset. Mortality, 30-day re-admissions, length of stay (LOS), hospital cost and net gain/loss in US dollars were determined for C-NS and C-S cases, with the C-NS-attributable burden estimated through propensity score matching. Three subgroups with adequate patient numbers were analysed: cUTI principal diagnosis, community onset; other principal diagnosis, community onset; and other principal diagnosis, hospital onset. FINDINGS: The C-NS-attributable mortality risk was significantly higher (58%) for the other principal diagnosis, hospital-onset subgroup alone (odds ratio 1.58, 95% confidence interval 1.14-2.20; P < 0.01). The C-NS-attributable risk for 30-day re-admission ranged from 29% to 55% (all P < 0.05). The average attributable economic impact of C-NS was 1.1-3.9 additional days LOS (all P < 0.05), US$1512-10,403 additional total cost (all P < 0.001) and US$1582-11,848 net loss (all P < 0.01); overall burden and C-NS-attributable burden were greatest in the other principal diagnosis, hospital-onset subgroup. CONCLUSION: Greater clinical and economic burden was observed in propensity-score-matched patients with C-NS infections compared with C-S infections, regardless of whether cUTI was the principal diagnosis, and this burden was most severe in hospital-onset infections.