Table 1.
Comparison of original and present study patient cohorts
| Measurea | Elias et al. | Present study |
|---|---|---|
| Study period | Nov 1997 to Feb 2011 | Jan 1 to Dec 1 2009 |
| ICU admissions, (n) | 92,866 | 90,733 |
| Patients, (n) | 92,886 | 77,040 |
| Hospitals, (n) | 2 | 151 |
| Patient age (years), mean (SD) | 61.6 (17.7) | 74.2 (12.2) |
| Male, n (%) | 53,658 (57.7) | 44,207 (48.7) |
| Nonwhite race n (%) | 18,762 (20.2) | 10,406 (11.5) |
| Patient type, n (%) | ||
| Medical | 46,683 (50.3) | 52,789 (58.2) |
| Charlson Comorbidity Index, n (%) | ||
| 0 – 1 | 35,277 (38.0) | 47,327 (52.2) |
| 2 – 3 | 31,587 (34.0) | 31,880 (35.1) |
| 4 – 6 | 20,907 (22.5) | 9,505 (10.5) |
| ≥7 | 5,115 (5.5) | 2,021 (2.2) |
| Elixhauser Index, median (IQR) | n/a | 3 (2,4) |
| COPS2, median (IQR) | n/a | 46 (19,70) |
| Sepsis, n (%) | 11,602 (12.5) | 10,872 (12.0) |
| Acute organ failure type, n (%) | ||
| Hematologic | 8,544 (9.2) | 2,260 (2.5) |
| Hepatic | 1,658 (1.8) | 905 (1.0) |
| Metabolic | 3,759 (4.0) | 4,319 (4.8) |
| Neurologic | 6,741 (7.3) | 3,459 (3.8) |
| Renal | 11,669 (12.6) | 14,716 (16.2) |
| Respiratory | 27,288 (29.4) | 12,145 (13.4) |
| Hospital LOS (days), mean (SD) | 12 (14.5) | 9.8 (9.9) |
| 30-day mortality, n (%) | 11,721 (12.6) | 15,995 (17.6) |
a
p<0.05 for comparisons of all patient-level factors between the original and present study cohorts
SD, standard deviation; IQR, interquartile range; COPS2, COmorbidity Point Score; LOS, length of stay