Table 1. Characteristics of ICU stays in each ICU type*†‡.
| Medical (N = 18128) |
Surgical (N = 7757) |
Post-Cardiac Surgical (N = 7740) |
Cardiac (N = 6451) |
Trauma (N = 5961) |
|
|---|---|---|---|---|---|
| Age (years) | 63.9 +/- 17.8 | 63.2 +/- 16.6 | 67.0 +/- 12.9 | 68.5 +/- 15.3 | 58.2 +/- 20.7 |
| Female sex | 48.2% | 46.6% | 34.3% | 42.2% | 39.1% |
| Race/Ethnicity | |||||
| Asian | 2.9% | 2.7% | 1.8% | 1.8% | 2.0% |
| Black | 12.4% | 7.9% | 3.4% | 6.9% | 5.6% |
| Hispanic | 3.8% | 3.6% | 2.7% | 2.3% | 4.1% |
| Other | 2.5% | 3.3% | 2.5% | 2.3% | 3.6% |
| Unknown | 6.3% | 6.0% | 14.4% | 12.8% | 9.9% |
| White | 72.1% | 76.5% | 75.2% | 73.9% | 74.8% |
| Comorbidities | |||||
| Diabetes mellitus | 28.6% | 23.9% | 30.0% | 32.4% | 17.4% |
| Heart failure | 29.6% | 15.8% | 28.3% | 51.0% | 11.8% |
| Hypertension | 50.8% | 53.8% | 68.6% | 61.6% | 41.4% |
| Chronic kidney disease | 15.6% | 9.1% | 9.5% | 19.0% | 5.7% |
| Liver disease | 12.6% | 12.0% | 2.6% | 4.4% | 4.5% |
| Metastatic cancer | 8.7% | 9.4% | 1.3% | 3.0% | 5.8% |
| Admit type | |||||
| Cardiovascular | 12.2% | 27.6% | 84.5% | 71.0% | 12.0% |
| Gastrointestinal | 16.1% | 16.0% | 1.2% | 3.4% | 8.9% |
| Infectious | 16.9% | 5.8% | 0.8% | 4.5% | 3.3% |
| Respiratory | 17.5% | 5.3% | 1.7% | 5.8% | 4.2% |
| Neoplasm | 7.9% | 16.3% | 2.8% | 2.0% | 9.0% |
| Injuries/Poisonings | 11.2% | 17.4% | 5.7% | 7.1% | 55.0% |
| Other | 18.2% | 11.6% | 3.3% | 6.2% | 7.6% |
| Admission serum creatinine (mg/dL) | 1.4 +/- 1.3 | 1.1 +/- 0.9 | 1.0 +/- 0.6 | 1.4 +/- 1.0 | 1.1 +/- 0.7 |
| Admission weight (kg) | 80.2 +/- 25.2 | 79.8 +/- 23.6 | 82.9 +/- 20.0 | 82.1 +/- 24.1 | 80.8 +/- 23.5 |
| First day urine output (L) | 1.9 +/- 1.4 | 1.9 +/- 1.2 | 2.2 +/- 1.1 | 2.0 +/- 1.4 | 2.0 +/- 1.3 |
| First day fluid balance (L) | 2.4 +/- 3.7 | 2.6 +/- 4.3 | 3.7 +/- 3.6 | 0.8 +/- 2.7 | 3.3 +/- 4.4 |
| ICU LOS (days) | 4.0 +/- 5.7 | 4.7 +/- 6.8 | 3.7 +/- 5.7 | 3.9 +/- 5.6 | 4.5 +/- 6.6 |
| ICU LOS fluid balance (L) | 4.5 +/- 8.9 | 5.6 +/- 9.9 | 3.1 +/- 6.4 | 1.6+/-7.6 | 6.4 +/- 9.7 |
| Mechanically ventilated | 37.0% | 47.7% | 86.7% | 31.9% | 54.3% |
*Categorical variables are given as percentages of each ICU type. Continuous variables are expressed as mean +/- standard deviation.
†Missingness was < 0.4% for admission serum creatinine and 3–6% for fluid balance variables for all ICU types. For admission weight, missingness was 7.3%, 11.2%, 2.4%, 9.7%, and 12.4% in the medical, surgical, post-cardiac surgical, cardiac, and trauma units respectively.
‡ All differences between the five ICUs were statistically significant by ANOVA or chi-squared testing.