Operational performance of validated physiologic scoring systems for predicting in-hospital mortality among critically ill emergency department patients.

OBJECTIVES: New Simplified Acute Physiology Score (SAPS) II, Morbidity Probability Model at admission (MPM0 II), and Logistic Organ Dysfunction System (LODS) have all demonstrated high accuracy for predicting mortality in intensive care unit populations. We tested the prognostic accuracy of these instruments for predicting mortality among a cohort of critically ill emergency department patients.

DESIGN: Secondary analysis of a randomized controlled trial.

SETTING: Urban, tertiary emergency department, census >100,000.

PATIENTS: Nontrauma emergency department patients admitted to an intensive care unit, aged >17 yrs, with initial emergency department vital signs consistent with shock (systolic blood pressure <100 mm Hg or shock index >1.0), and with agreement of two independent observers for at least one sign and symptom of inadequate tissue perfusion.

INTERVENTIONS: Emergency department variables needed for calculation of each scoring system were prospectively collected, and published formulas were used to calculate the probability of in-hospital death for each scoring system. The main outcome was actual in-hospital mortality. The area under the receiver operating characteristic curve was used to evaluate the predictive ability of each scoring system.

MEASUREMENTS AND MAIN RESULTS: Ninety-one of 202 patients (45%) were included. The mean age was 56 +/- 16 yrs, 42% were female, the mean initial systolic blood pressure was 84 +/- 13 mm Hg, and the average length of stay in the emergency department was 4.2 +/- 2.0 hrs. The in-hospital mortality rate was 21%. The area under the receiver operating characteristic curve for calculated probability of in-hospital mortality for SAPS II was 0.72 (95% confidence interval, 0.57-0.87), for MPM0 II 0.69 (95% confidence interval, 0.54-0.84), and for LODS 0.60 (95% confidence interval, 0.45-0.76).

CONCLUSIONS: Using variables available in the emergency department, three previously validated intensive care unit scoring systems demonstrated moderate accuracy for predicting in-hospital mortality.