title: National study of emergency department observation services.
abstract: OBJECTIVE
  The objective was to describe patient and facility characteristics of emergency department (ED) observation services in the United States.
  
  
  METHODS
  The authors analyzed the 2007 National Hospital Ambulatory Medical Care Survey (NHAMCS). Characteristics of EDs with observation units (OUs) were compared to those without, and patients with a disposition of ED observation were compared to those with a "short-stay" (<48 hour) hospital admission. Results are descriptive and without formal statistical comparisons for this observational analysis.
  
  
  RESULTS
  An estimated 1,746 U.S. EDs (36%) reported having OUs, of which 56% are administratively managed by ED staff. Fifty-two percent of hospitals with ED-managed OUs are in an urban location, and 89% report ED boarding, compared to 29 and 65% of those that do not have an OU. The admission rate is 38% at those with ED-managed OUs and 15% at those without OUs. Of the 15.1% of all ED patients who are kept in the hospital following an ED visit, one-quarter are kept for either a short-stay admission (1.8%) or an ED observation admission (2.1%). Most (82%) ED observation patients were discharged from the ED. ED observation patients were similar to short-stay admission patients in terms of age (median = 52 years for both, interquartile range = 36 to 70 years), self-pay (12% vs. 10%), ambulance arrival (37% vs. 36%), urgent/emergent triage acuity (77% vs. 74%), use of ≥1 ED medication (64% vs.76%), and the most common primary chief complaints and primary diagnoses.
  
  
  CONCLUSIONS
  Over one-third of U.S. EDs have an OU. Short-stay admission patients have similar characteristics as ED observation patients and may represent an opportunity for the growth of OUs.
authors: Department of Emergency Medicine, University of Colorado School of Medicine, Aurora, USA. jenniferwiler@ucdenver.edu
authors: Jennifer L
authors: JL
authors: Wiler
authors: Michael A
authors: MA
authors: Ross
authors: Adit A
authors: AA
authors: Ginde
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004632:Emergency Medical Services / Q000706:statistics & numerical data; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data*; D005260:Female; D019538:Health Care Surveys; D006757:Hospital Units / Q000706:statistics & numerical data*; D006801:Humans; D007902:Length of Stay / Q000706:statistics & numerical data*; D008297:Male; D008875:Middle Aged; D019370:Observation; D010343:Patient Admission / Q000706:statistics & numerical data*; D014481:United States; D055815:Young Adult