Empirical antimicrobials (%) | Without risk factors for Pseudomonas infection (n=3852) | With risk factors for Pseudomonas infection (n=1864)† | |||
Age <65 years and not in ICU (n=1881) | Age <65 years and in ICU (n=79) | Age ≥65 years and not in ICU (n=1742) | Age ≥65 years and in ICU (n=150) | ||
β-Lactams (antipseudomonal) | 178 (4.6)‡ | 21 (0. 5) | 407 (10.6)‡ | 58 (1.5) | 541 (29.0) |
β-Lactams | 331 (8.6) | 9 (0.2) | 482 (12.5) | 20 (0.5) | 345 (18.5) |
Fluoroquinolones | 502 (13.0) | 10 (0.3) | 273 (7.1) | 6 (0.2) | 252 (13.5) |
Macrolides | 20 (0.5) | 0 (0.0) | 17 (0.4) | 0 (0.0) | 10 (0.5) |
β-Lactams (antipseudomonal)+fluoroquinolones | 201 (5.2)‡ | 13 (0.3)‡ | 189 (4.9)‡ | 30 (0.8) | 238 (12.8) |
β-Lactams+fluoroquinolones | 302 (7.8)‡ | 3 (0.1)‡ | 166 (4.3)‡ | 9 (0.2) | 177 (9.5) |
β-Lactams+macrolides | 160 (4.2) | 2 (0.1) | 64 (1.7) | 2 (0. 1) | 55 (3.0) |
β-Lactams (antipseudomonal)+macrolides | 50 (1.3)‡ | 0 (0.0) | 45 (1.2)‡ | 2 (0.1) | 58 (3.1) |
Fluoroquinolones+macrolides | 24 (0.6) | 0 (0.0) | 11 (0.3) | 0 (0.0) | 6 (0.3) |
Anti-MRSA drugs | 9 (0.2)‡ | 8 (0.2) | 12 (0.3)‡ | 6 (0.2) | 29 (1.6) |
Others | 104 (2.7) | 13 (0.3) | 76 (2.0) | 17 (0.4) | 153 (8.2) |
*Data on empirical antimicrobial regimens in 112 patients were missing.
†Risk factors for pseudomonal infection was defined as chronic airway disease (bronchiectasis or chronic obstructive pulmonary disease) or healthcare-associated pneumonia according to Infectious Diseases Society America/American Thoracic Society criteria.14
‡Overtreatment was defined as (1) use of antipseudomonal β-lactams or β-lactams+fluoroquinolones in hospitalised (not in ICU) patients without risk factors for pseudomonal infection; (2) use of β-lactams (antipseudomonal or not)+fluoroquinolones in ICU patients aged <65 years without risk factors for pseudomonal infection; (3) use of anti-MRSA drugs in hospitalised (not in ICU) patients (use of anti-MRSA drugs in ICU patients with MRSA risk after influenza virus infection was considered adequate).13
CAP, community-acquired pneumonia; ICU, intensive care unit;MRSA.methicillin-resistant Staphylococcus aureus