title: [Modified overcrowd index in emergency room].
abstract: BACKGROUND
  Overcrowd of emergency rooms affects efficiency and quality of medical care.
  
  
  OBJECTIVE
  To describe the mathematical-computational system modified overcrowd index which measures in real time and in four levels of warnings (non crowded, crowded, overcrowded and extreme overcrowded) emergency room saturation in a network of hospitals, from only seven simple variables (number of available beds, physicians and nurses, number of patients in the waiting room, in medical consultation and admitted for further evaluation, as well as number of critically ill patients admitted).
  
  
  METHODS
  The modified overcrowd index was exhaustively tested with 245,280 virtual transactions from seven hospitals in an uninterrupted schedule basis simulating hourly surveillance for four years.
  
  
  RESULTS
  From 224 episodes of overcrowd, 216 (97%) where correctly identified and verified by the network of hospitals warnings, its time series also provided useful information about available personnel and resource distribution within the hospital network.
  
  
  CONCLUSIONS
  Modified overcrowd index is an efficient tool detecting emergency room overcrowd outbreaks in a network of hospitals.
authors.affiliation: Subdirección de Epidemiología Hospitalaria y Control de Calidad de la Atención Médica, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, México, D.F. polanco@unam.mx.
authors.forename: Carlos
authors.initials: C
authors.lastname: Polanco-González
authors.forename: Jorge Alberto
authors.initials: JA
authors.lastname: Castañón-González
authors.forename: Thomas
authors.initials: T
authors.lastname: Buhse
authors.forename: José Lino
authors.initials: JL
authors.lastname: Samaniego-Mendoza
authors.forename: Rocío
authors.initials: R
authors.lastname: Arreguín-Nava
authors.forename: Sebastián
authors.initials: S
authors.lastname: Villanueva-Martínez
mesh_terms: D004636:Emergency Service, Hospital / Q000706:statistics & numerical data*; D006801:Humans; D015233:Models, Statistical