Healthcare Resource Utilization and Cost Related to Nosocomial Pneumonia Caused by Staphylococcus aureus and Pseudomonas aeruginosa in France: A 2010-2011 Population-Based Cohort Study Using a National Claims Database

Background: Nosocomial pneumonia is a leading cause of hospital-acquired infection. However, evidence is limited regarding resource utilization and healthcare costs associated with nosocomial pneumonia in France. Methods: This retrospective case-control study used a nationwide hospital claims database for cases of nosocomial pneumonia caused by Staphylococcus aureus or Pseudomonas aeruginosa. Hospital stay costs were retrieved during index hospitalization and at 30-days and 90-days post-discharge. Cost was calculated using Diagnosis Related Group (DRG) codes and daily cost estimates. Results: Of 7,793 patients discharged with S. aureus or P. aeruginosa pneumonia between January 2010 and December 2011, 1,453 and 1,449 cases were included, respectively. Cases were matched with controls in terms of DRG root, age, gender, Charlson comorbidity score, and hospital region. Cases demonstrated significantly higher Charlson comorbidity scores (p<0.01) and almost four times higher mean index hospitalization duration (p<0.001), critical care unit stays (p<0.001), mechanical ventilation procedures (p<0.001), and mortality (p<0.001) compared to matched controls. Univariate analysis indicated significantly higher cost of treating cases compared to controls in terms of DRG (S. aureus cohort: €21,540 vs. €6,426; P. aeruginosa cohort: €20,732 vs. €6,172; p<0.001) and daily valuation costs (S. aureus cohort: €28,063 vs. €5,976; P. aeruginosa cohort: €30,827 vs. €5,819; p<0.001). Multivariate analysis showed that nosocomial pneumonia increased mean DRG costs at 90 days by €13,500 to €16,700 for S. aureus cohort, and by €13,300 to €20,200 for P. aeruginosa cohort. Conclusions: Nosocomial pneumonia due to S. aureus or P. aeruginosa was associated with considerable patient morbidity and hospital costs in France.