title: [Relative effects of external and internal factors on emergency department efficiency].
abstract: BACKGROUND
  To know the relative effect of external and internal factors on emergency department (ED) efficiency.
  
  
  METHODS
  Along 3 consecutive weeks we compute at 3 hours-interval the number or patient waiting for visit and the mean waiting time for visit (efficiency markers), the number of patients arriving to ED (external pressure marker) and the number of patients remaining in ED after beginning the visit (internal pressure marker), which was divided in ED-related factors, hospital-related factors, ED-hospital interelation-related factors, or not caused by ED nor hospital-related factors.
  
  
  RESULTS
  Only the increase of internal pressure was associated with a decline in ED efficiency (p < 0.001). ED-related and hospital-related factors were those significantly associated with such a decline (p < 0.05 and p < 0.01, respectively).
  
  
  CONCLUSIONS
  Internal pressure generated by the own ED exerts a prominent role in its dysfunction; therefore, policies addressed to reduce such internal pressure should be encouraged.
authors.affiliation: Servicio de Urgencias. Hospital Clínic. Barcelona. omiro@clinic.ub.es
authors.forename: O
authors.initials: O
authors.lastname: Miró
authors.forename: M
authors.initials: M
authors.lastname: Sánchez
authors.forename: B
authors.initials: B
authors.lastname: Coll-Vinent
authors.forename: J
authors.initials: J
authors.lastname: Millá
mesh_terms: D017598:Efficiency, Organizational; D004632:Emergency Medical Services / Q000458:organization & administration*; D013030:Spain; D013997:Time Factors