Context Early identification of nontrauma patients in need of critical care services in the
emergency setting may improve triage decisions and facilitate regionalization of critical care.
Objectives To determine the out-of-hospital clinical predictors of critical illness and to
characterize the performance of a simple score for out-of-hospital prediction of development
of critical illness during hospitalization. Design and Setting Population-based cohort study of
an emergency medical services (EMS) system in greater King County, Washington …

This retrospective cohort study from Washington identified adult patients with non-traumatic,
non-cardiac arrest and developed an out-of-hospital clinical prediction model of critical
illness. All non-trauma, non-cardiac arrest patients who activated the Emergency Medical
Services from 2002 to 2006 in King County with complete records were linked to hospital
discharge data, and then randomly assigned to either development (n= 87,266) or validation
cohort (n= 57,647). Out-of-hospital and in-hospital data were reviewed for predictors of …