Relationship of the clinical acuity & complexity to the outcome of an emergency medical admission.

BACKGROUND: An Illness Severity and Co-morbidity composite score can predict 30-day mortality outcome. METHODS: We computed a summary risk score (RS) for emergency medical admissions and used cluster analysis to define four subsets Results: Four cluster groups were defined. Cluster 1 - RS 7 points (IQR 5, 8) Cluster 2 - 9 (IQR 8, 11), Cluster 3 - 12 (IQR 11, 13) and Cluster 4 - 14 (IQR 13, 15). Clusters predicted 30-day in hospital mortality OR 1.86 (95%CI: 1.82, 1.92); respective rates 1.4% (95% CI: 1.3%, 1.6%), 3.4% (95% CI: 3.1%, 3.6%), 7.8% (95% CI: 7.5%, 8.1%) and 16.5% (95% CI: 15.7%, 17.2%). CONCLUSION: Cluster grouping of Risk Score was age related; strongest outcome determinant was Acute Illness Severity.