Table 1.
Characteristics of study population and participating units
| Characteristics | LowABR countries | HighABR countries | p-value | |
|---|---|---|---|---|
| Of ICUs | N = 54 | N = 231 | ||
| Staffed ICU beds, n (%) | ||||
| <7 | 14 (25.9) | 67 (29.0) | 0.9 | |
| 7-14 | 30 (55.6) | 122 (52.8) | ||
| 15+ | 10 (18.5) | 42 (18.2) | ||
| Nurse:patient, n (%) | ||||
| >1:1 | 19 (35.2) | 16 (6.9) | <0.001 | |
| 1:1-1:1.49 | 14 (25.9) | 42 (18.2) | ||
| 1:1.5-1:1.99 | 18 (33.3) | 78 (33.8) | ||
| <1:2 | 3 (5.6) | 95 (41.1) | ||
| 24-hr in-house intensivist | 48 (88.9) | 231 (100%) | <0.001 | |
| Of patients | N = 558 | N = 2204 | ||
| Age, median (25-75 percentile) | 65 (53-74) | 65 (51-74) | 0.574 | |
| SAPS II score, median (25-75 percentile) | 31 (25-39) | 34 (26-44) | <0.001 | |
| SOFA score, median (25-75 percentile) | 5 (3-8) | 5 (3-8) | 0.806 | |
| Length of stay in days in ICU prior to study day, median (25-75 percentile) | 1 (0-6) | 4 (0-14) | <0.001 | |
| Infected | 255 (45.7) | 1187 (53.9) | 0.001 | |
| Type of admission, n (%) | Surgical, elective | 203 (36.5) | 455 (20.7) | <0.001 |
| Surgical, emergency | 200 (36.0) | 952 (43.2) | ||
| Medical | 114 (20.5) | 534 (24.3) | ||
| Trauma | 39 (7.0) | 261 (11.9) | ||
| Admission source, n (%) | OR/recovery | 205 (37.7) | 472 (21.5) | < 0.001 |
| ED/ambulance | 111 (20.4) | 680 (31.0) | ||
| Hospital ward | 160 (29.4) | 713 (32.5) | ||
| Other hospital | 61 (11.2) | 273 (12.4) | ||
| Other | 7 (1.3) | 55 (2.5) | ||
| Main reason for admission, n (%) | Surveillance/monitoring | 158 (28.3) | 336 (15.2) | < 0.001 |
| Neurological | 56 (10.0) | 350 (15.9) | ||
| Respiratory | 119 (21.3) | 527 (23.9) | ||
| Cardiovascular | 119 (21.3) | 579 (26.3) | ||
| Renal | 5 (0.9) | 33 (1.5) | ||
| Digestive/liver | 53 (9.5) | 154 (7.0) | ||
| Trauma | 36 (6.5) | 198 (9.0) | ||
| Other | 12 (2.2) | 27 (1.2) | ||
| Co-morbidities, n (%) | COPD | 77 (13.8) | 457 (20.7) | <0.001 |
| Haematological cancer | 11 (2.0) | 49 (2.2) | 0.715 | |
| Cancer | 82 (14.7) | 341 (15.5) | 0.649 | |
| IDDM | 42 (7.5) | 221 (10.0) | 0.072 | |
| Heart Failure (NYHA III-IV) | 59 (10.6) | 231 (10.5) | 0.949 | |
| CRF | 14 (2.5) | 165 (7.5) | <0.001 | |
| HIV | 2 (0.4) | 15 (0.7) | 0.385 | |
| Cirrhosis | 14 (2.5) | 65 (2.9) | 0.577 | |
| Immunosuppression | 24 (4.3) | 95 (4.3) | 0.992 | |
| Number of co-morbidities, n (%) | None | 282 (50.5) | 1011 (45.9) | 0.029 |
| 1 | 195 (34.9) | 746 (33.8) | ||
| 2 | 61 (10.9) | 313 (14.2) | ||
| 3 | 16 (2.9) | 103 (4.7) | ||
| >3 | 4 (0.7) | 31 (1.4) | ||
| Treatments, n (%) | Mechanical ventilation | 359 (64.7) | 1388 (63.1) | 0.502 |
| Haemofiltration or haemodialysis | 47 (8.5) | 171 (7.8) | 0.591 | |
| Length of stay, median (25-75 percentile) | ICU | 5 (1-19) | 12 (3-31) | < 0.001 |
| Hospital | 16 (7-37) | 24 (10-54) | <0.001 | |
| Mortality | ICU | 83 (15.4) | 408 (20.0) | 0.016 |
| Hospital | 116 (21.5) | 551 (27.0) | 0.01 | |
OR, operating room; ED, emergency department; COPD, chronic obstructive pulmonary disease; IDDM, insulin-dependent diabetes mellitus; NYHA III-IV, New York Heart Association class III-IV; CRF, chronic renal failure; HIV, human immunodeficiency virus.