CARING FOR THE CRITICALLY ILL PATIENT Prediction of Critical Illness During Out-of-Hospital Emergency Care

HOSPITALS VARY WIDELY IN quality of critical care. Consequently, the outcomes of critically ill patients may be improved by concentrating care at more experienced centers. By centralizing patients who are at greater risk of mortality in referral hospitals, regionalized care in critical illness may achieve improvements in outcome similar to trauma networks. In 2006, the Institute of Medicine called for a regionalized, coordinated system of emergency care for high-risk patients, one in which patients in most need of highintensity acute care are distributed to centers with the greatest expertise in caring for the critically ill. Current out-of-hospital triage of noninjured, critically ill patients uses dispatch criteria, subjective emergency medical services (EMS) assessments, coordination by medical command officers, and patient preference. In specific conditions such as coronary artery disease and stroke, out-of-hospital care providers use objective tools to triage and risk-stratify prehospital patients for early treatment and choice of destination. However, these subjective and disease-specific assessments alone may not be sufficient for triage in general populations at risk of critical illness. Future development of regionalized systems of acute care will require objective, routinely measured predictors that are associated with important clinical end points in a heterogeneous population. An objective triage tool may also identify patients for early treatment by out-of-hospital care providers. Wesoughttodevelopatool forprediction of critical illness during out-ofhospitalcare innoninjured,non–cardiac arrestpatients.Usingapopulation-based cohort of EMS records linked to hospital discharge data, we hypothesized that objective,out-of-hospitalfactorscoulddiscriminatebetweenpatientswhowereand