Table 1 Information collected on all patients who remained in the intensive care unit (ICU) on day 5.
Variable | Measurement | Reference Group* (if applicable) |
|---|---|---|
Day 1 | Â | Â |
Acute Physiology Score (APS) Variables | Weight determined by most abnormal value within initial first APACHE day, sum of weights equals the APS, which ranges 0 to 252. Five spline terms added. Variables include pulse rate, mean blood pressure, temperature, respiratory rate, PaO2 : FiO2 ratio (or A-aD02 for intubated patients with FIO2 > 0.5), hematocrit, white blood cell count, creatinine, urine output, blood urea nitrogen, sodium, albumin, bilirubin, glucose, acid base abnormalities, and neurological abnormalities based on Glasgow Coma Score. Continuous measure. Three spline terms added in the complex regression model. | N/A |
Chronic Health Items (CHIs) | AIDS, cirrhosis, hepatic failure, immunosupression, lymphoma, leukemia or myeloma, metastatic tumor. Not used for elective surgery patients. Binary variable for > 0 CHIs. Complex model had a binary variable for each CHI separately. | N/A |
ICU Admission Diagnosis | 59 categories | Acute Myocardial Infarction |
ICU Admission Source | Floor, operating/recovery room, other hospital, other admission source. | Direct admission |
Length of Stay before ICU Admission | Square root. Two spline terms added in the complex regression model. | N/A |
Age | Continuous measure. Three spline terms added in the complex regression model | N/A |
PaO2 : FiO2 Ratio on Day 1 | Divided by 10; Continuous measure. Three spline terms added in the complex regression model.. | N/A |
Emergency Surgery? | Binary | No |
Ventilated on Day 1? | Binary | No |
Unable to Assess Glasgow Coma Score on Day 1? | Binary | No |
Thrombolytic Therapy (for patients with AMI)? | Binary | No |
Rescaled Glasgow Coma Score on Day 1 | 12 - Glasgow Coma Score | N/A |
Day 1 ICU Length of Stay Prediction | See reference (10) | N/A |
Readmission to ICU? | Binary | No |
Day 5 | Â | Â |
Acute Physiology Score (APS) Variables | Same as for day 1 but taken on day 5. Continuous measure. Three spline terms added in the complex regression model. | N/A |
Ventilated on Day 5? | Binary | No |
Unable to Assess Glasgow Coma Score on Day 5? | Binary | No |
PaO2 : FiO2 Ratio on Day 5 | Divided by 10; Continuous measure | N/A |
Rescaled Glasgow Coma Score on Day 5 | 12 - Glasgow Coma Score | N/A |
Delta APS | APS on Day 4 - APS on Day 5 | N/A |