Table 1.
Characteristics of the study population stratified by whether they experienced the primary outcome of in-hospital death or intensive care unit length of stay ≥ 7 days. All clinical variables were measured during the first 48 hours of the hospital admission.
| Characteristic, n (%) | All | Died or ICU LOS ≥ 7 days | |
|---|---|---|---|
| Yes | No | ||
| Patient admissions | 25,947 | 5,504 (21.2) | 20,443 (78.8) |
| In-hospital death | 1,861 (7.8) | 1,861 (33.8) | 0 (0) |
| ICU LOS ≥ 7 days | 4,564 (17.6) | 4,564 (82.9) | 0 (0) |
| Age (years), median (IQR) | 64.1 (51.3 – 76.3) | 66.9 (53.6 – 77.8) | 63.4 (50.1 – 75.8) |
| ICU LOS (days), median (IQR) | 2.5 (1.4 – 5.0) | 11.0 (7.8 – 17.6) | 2.0 (1.2 – 3.2) |
| Hospital LOS (days), median (IQR) | 6.9 (4.5 – 11.6) | 16.5 (10.7 – 25.0) | 6.0 (4.2 – 8.5) |
| Male | 14,958 (57.5) | 3,161 (57.4) | 11,797 (57.7) |
| Admission type | |||
| Emergency | 20,867 (80.4) | 4,837 (87.9) | 16,030 (78.4) |
| Elective | 4,341 (16.7) | 451 (8.2) | 3,890 (19.0) |
| Urgent | 739 (2.8) | 216 (3.9) | 523 (2.6) |
| Initial ICU type | |||
| MICU | 9,622 (37.1) | 2,168 (39.4) | 7,454 (36.5) |
| CSRU | 4,935 (19.0) | 686 (12.5) | 4,249 (20.8) |
| CCU | 4,030 (15.5) | 765 (13.9) | 3,265 (16.0) |
| SICU | 4,024 (15.5) | 1,031 (18.7) | 2,993 (14.6) |
| TSICU | 3,329 (12.8) | 853 (15.5) | 2,476 (12.1) |
| Not recorded | 7 (<0.1) | 1 (<0.1) | 6 (<0.1) |
| Self-reported race or ethnicity | |||
| White | 18,461 (71.1) | 3,916 (71.4) | 14,545 (71.1) |
| Black | 2,475 (9.5) | 407 (7.4) | 2,068 (10.1) |
| Hispanic or Latino | 848 (3.3) | 151(2.7) | 697 (3.4) |
| Asian | 563 (2.2) | 97 (1.8) | 466 (2.3) |
| Other/Unknown | 3,600 (13.9) | 933 (17.0) | 2,667 (13.0) |
| Modified Elixhauser score, median (IQR) | 8 (2 – 15) | 12 (6 – 19) | 6 (1 – 13) |
| Clinical deterioration | |||
| Mechanical ventilation | 4,512 (17.4) | 1,926 (35.0) | 2,586 (12.6) |
| Cardiac arrest | 206 (0.8) | 91 (1.7) | 115 (0.6) |
| ICU transfer | 25,614 (98.7) | 5,427 (98.6) | 20,187 (98.7) |
| Laboratory data, median (IQR) | |||
| Creatinine, highest | 1.10 (0.80 – 1.60) | 1.20 (0.90 – 2.10) | 1.00 (0.80 – 1.50) |
| WBCs, highest | 13.0 (9.70 – 17.10) | 14.8 (10.9 – 19.8) | 12.6 (9.5 – 16.5) |
| Platelets, lowest | 176 (125 – 235) | 164 (106 – 228) | 179 (130 – 237) |
| Total bilirubin, highest | 1.5 (0.6 – 1.5) | 1.5 (0.6 – 1.5) | 1.5 (0.6 – 1.5) |
| PaO2, lowest | 103 (93 – 103) | 103 (71 – 103) | 103 (103 – 103) |
| Potassium, highest | 4.5 (4.2 – 4.9) | 4.6 (4.2 – 5.1) | 4.5 (4.1 – 4.9) |
| Vital signs, median (IQR) | |||
| Urine output (cc/kg/hr) | 0.85 (0.57 – 0.90) | 0.85 (0.53 – 0.91) | 0.85 (0.58 – 0.90) |
| Glasgow coma scale, lowest | 9 (7 – 14) | 8 (3 – 9) | 9 (9 – 15) |
| Systolic blood pressure (mmHg), lowest | 89 (79 – 101) | 83 (70 – 94) | 91 (81 – 102) |
| Heart rate (beats per minute), highest | 69 (60 – 78) | 69 (60 – 80) | 68 (60 – 77) |
| Temperature (°C), highest | 36.0 (35.6 – 36.4) | 35.9 (35.4 – 36.4) | 36.1 (35.6 – 36.4) |
| Clinical notes | |||
| Total raw word count, median (IQR) | 1,023 (562 – 2,266) | 1,410 (956 – 2,292) | 899 (501 – 2,247) |
| Number of notes, median (IQR) | 6 (4 – 11) | 8 (6 – 12) | 5 (3 – 10) |
Abbreviations: ICU = intensive care unit, LOS = length of stay, IQR = interquartile range, MICU = medical intensive care unit, CSRU = cardiothoracic surgery care unit, CCU = cardiac care unit, SICU = surgical intensive care unit, TSICU = trauma surgery intensive care unit, WBC = white blood cell count, PaO2 = partial pressure of arterial oxygen