title: The impact of an emergency fee increase on the composition of patients visiting emergency departments.
abstract: OBJECTIVE
  This study aimed to test our hypothesis that a raise in the emergency fee implemented on March 1, 2013 has increased the proportion of patients with emergent symptoms by discouraging non-urgent emergency department visits.
  
  
  METHODS
  We conducted an analysis of 728 736 patients registered in the National Emergency Department Information System who visited level 1 and level 2 emergency medical institutes in the two-month time period from February 1, 2013, one month before the raise in the emergency fee, to March 31, 2013, one month after the raise. A difference-in-difference method was used to estimate the net effects of a raise in the emergency fee on the probability that an emergency visit is for urgent conditions.
  
  
  RESULTS
  The percentage of emergency department visits in urgent or equivalent patients increased by 2.4% points, from 74.2% before to 76.6% after the policy implementation. In a group of patients transferred using public transport or ambulance, who were assumed to be least conscious of cost, the change in the proportion of urgent patients was not statistically significant. On the other hand, the probability that a group of patients directly presenting to the emergency department by private transport, assumed to be most conscious of cost, showed a 2.4% point increase in urgent conditions (p<0.001). This trend appeared to be consistent across the level 1 and level 2 emergency medical institutes.
  
  
  CONCLUSIONS
  A raise in the emergency fee implemented on March 1, 2013 increased the proportion of urgent patients in the total emergency visits by reducing emergency department visits by non-urgent patients.
authors.affiliation: Department of Health Policy and Management, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Hyemin
authors.initials: H
authors.lastname: Jung
authors.affiliation: Department of Health Policy and Management, Seoul National University College of Medicine, Seoul, Korea ; Institute of Health Policy and Management, Seoul National University Medical Research Center, Seoul, Korea.
authors.forename: Young Kyung
authors.initials: YK
authors.lastname: Do
authors.affiliation: Department of Health Policy and Management, Seoul National University College of Medicine, Seoul, Korea ; Institute of Health Policy and Management, Seoul National University Medical Research Center, Seoul, Korea.
authors.forename: Yoon
authors.initials: Y
authors.lastname: Kim
authors.affiliation: Department of Health Policy and Management, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Junsoo
authors.initials: J
authors.lastname: Ro
mesh_terms: D000328:Adult; D000552:Ambulances; D004180:Direct Service Costs; D004636:Emergency Service, Hospital / Q000191:economics* / Q000706:statistics & numerical data*; D005249:Fees and Charges; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012044:Regression Analysis; D013997:Time Factors
keywords: Difference-in-difference; Emergency fee; Hospital emergency service; Overcrowding