Table 1.
Characteristics of the study population
| Characteristic | Total population | Patients with VAP | Patients without VAP |
| Number of patients | 936 | 209 | 727 |
| Age (years) | 65 (50 to 75) | 64 (54 to 74) | 65 (48 to 75) |
| Male sex | 552 (59.0) | 125 (59.8) | 427 (58.7) |
| Charlson score at admissiona | |||
| 0 | 335 (35.8) | 69 (33.0) | 266 (36.6) |
| 1 to 2 | 326 (34.8) | 91 (43.5) | 235 (32.3) |
| 3 to 5 | 184 (19.7) | 34 (16.3) | 150 (20.6) |
| > 5 | 91 (9.7) | 15 (7.2) | 76 (10.5) |
| APACHE II score at admissionb | |||
| < 26 | 367 (40.3) | 74 (37.2) | 293 (41.2) |
| 26 to 30 | 170 (18.7) | 37 (18.6) | 133 (18.7) |
| > 30 | 373 (41.0) | 88 (44.2) | 285 (40.1) |
| Nursing acuity score at admission | 226 (199 to 226) | 226 (200 to 226) | 226 (196 to 226) |
| Admission diagnosis | |||
| Infectious diseasea | 238 (25.4) | 70 (33.5) | 168 (23.1) |
| Cardiovascular condition | 315 (33.7) | 76 (36.4) | 239 (32.9) |
| Pulmonary disease | 139 (14.9) | 27 (12.9) | 112 (15.4) |
| Othera | 244 (26.1) | 36 (17.2) | 208 (28.6) |
| ICU stay (days)a | 6 (3 to 11) | 15 (10 to 23) | 5 (3 to 8) |
| Duration of mechanical ventilation (days)a | 3 (2 to 8) | 11 (6 to 19) | 3 (2 to 6) |
| ICU mortality | 297 (31.7) | 70 (33.5) | 227 (31.2) |
| Hospital stay (days)a | 18 (7 to 38) | 29 (17 to 67) | 14 (5 to 32) |
| Hospital mortality | 381 (40.7) | 94 (45.0) | 287 (39.5) |
Values are expressed as numbers (%) or median (interquartile range) for continuous variables. aSignificant difference between patients with and without VAP (P < 0.05). bTwenty-six missing values. APACHE, Acute Physiology and Chronic Health Evaluation; ICU, intensive care unit; VAP, ventilator-associated pneumonia.