Trends of Incidence and Risk Factors of Ventilator-Associated Pneumonia in Elderly Patients Admitted to French ICUs Between 2007 and 2014

OBJECTIVES: To assess trends and risk factors of ventilator-associated pneumonia according to age, particularly in the elderly admitted to French ICUs between 2007 and 2014. DESIGN: Multicenter, prospective French national Healthcare-Associated Infection surveillance network of ICUs ("Reseau REA-Raisin"). SETTINGS: Two-hundred fifty six ICUs in 246 settings in France. PATIENTS: Included were all adult patients hospitalized greater than or equal to 48 hours in ICUs participating in the network. INTERVENTIONS: Ventilator-associated pneumonia surveillance over time. MEASUREMENTS AND MAIN RESULTS: Overall and multidrug-resistant organism-related ventilator-associated pneumonia incidence rates were expressed per 1,000 intubation days at risk. Age was stratified into three groups: young (18-64 yr old), old (65-74 yr old), and very old (75+ yr old). Age-stratified multivariate mixed-effects Poisson regressions were undertaken to assess trends of ventilator-associated pneumonia incidence over time, with center as the random effect. Ventilator-associated pneumonia risk factors were also evaluated. Of 206,223 patients, 134,510 were intubated: 47.8% were young, 22.3% were old, and 29.9% were very old. Ventilator-associated pneumonia incidence was lower in the very old group compared with the young group (14.51; 95% CI, 16.95-17.70 vs 17.32; 95% CI, 16.95-17.70, respectively, p < 0.001). Methicillin-resistant Staphylococcus aureus and third-generation cephalosporin-resistant Enterobacteriaceae were identified more frequently in very old patients (p < 0.001 and 0.014, respectively). Age-stratified models disclosed that adjusted ventilator-associated pneumonia incidence decreased selectively in the young and old groups over time (adjusted incidence rate ratios, 0.88; 95% CI, 0.82-0.94; p < 0.001 and adjusted incidence rate ratios, 0.95; 95% CI, 0.86-1.04; p = 0.28, respectively). Male gender and trauma were independently associated with ventilator-associated pneumonia in the three age groups, whereas antibiotics at admission was a protective factor. Scheduled surgical ICU and immunodeficiency were risk factors of ventilator-associated pneumonia in the old group (p = 0.003). CONCLUSIONS: Ventilator-associated pneumonia incidence is lower but did not decrease over time in very old patients compared with young patients.