Data collection
comorbidity
The following variables were obtained during the first 24 h of admission: demographic data, comorbidities (i.e., Charlson comorbidity index), urine output, laboratory data, invasive interventions, severity (i.e., Simplified Acute Physiology Score II [SAPS II]), and outcomes. The data was taken directly from the critical care information systems, electronic hospital records, laboratory results, and vital signs monitors, as described before [