title: No more winter crisis? Forecasting daily bed requirements for emergency department admissions to hospital.
abstract: OBJECTIVE
  We hypothesized that age, calendar variables, and clinical influenza epidemics may have an impact on the number of daily through-emergency department (ED) hospitalizations. The aim of our study was to elaborate a pragmatic tool to predict the daily number of through-ED hospitalizations.
  
  
  METHODS
  We carried out a prospective-observational study including data from 18 ED located in the Paris metropolitan area. Daily through-ED hospitalizations numbers from 2007 to 2010 were modelized to forecast the year 2011 using a general linear model by age groups (<75-years; ≥75-years) using calendar variables and influenza epidemics as explanatory variables. Lower and higher limits forecast with the 95% confidence interval of each explanatory variable were calculated.
  
  
  RESULTS
  2 741 974 ED visits and 518 857 through-ED hospitalizations were included. We found a negative trend (-2.7%) for hospitalization visits among patients less than 75 years of age and an increased trend (+6.2%) for patients of at least 75 years of age. Calendar variables were predictors for daily hospitalizations for both age groups. Influenza epidemic period was not a predictor for hospitalizations in patients less than 75 years of age; among patients of at least 75 years of age, significant value was found only in models excluding months. When forecasting hospitalizations, 70% for patients less than 75 years of age and 66.8% for patients of at least 75 years of age of daily predicted values were included in the forecast limits.
  
  
  CONCLUSIONS
  Daily number of emergency hospitalizations could be predicted on a regional basis using calendar variables with a low level of error. Forecasting through-ED hospitalizations requires to differentiate between elderly and younger patients, with a low impact of influenza epidemic periods in elders and absent in youngest patients.
authors.affiliation: Hospital Saint Camille, Emergency Department, Bry Sur Marne, France.|Study Group on Efficiency and Quality in non-scheduled activities, Paris, France.
authors.forename: Mathias
authors.initials: M
authors.lastname: Wargon
authors.affiliation: Medical Organisation Department - Emergencies and Intensive Cares, Assistance Publique-Hôpitaux de Paris, Paris, France.|Regional Center of Watchfulness and Action Paris Area Assistance Publique-Hôpitaux de Paris, Paris, France.
authors.forename: Dominique
authors.initials: D
authors.lastname: Brun-Ney
authors.affiliation: Medical Organisation Department - Emergencies and Intensive Cares, Assistance Publique-Hôpitaux de Paris, Paris, France.|Regional Center of Watchfulness and Action Paris Area Assistance Publique-Hôpitaux de Paris, Paris, France.
authors.forename: Laure
authors.initials: L
authors.lastname: Beaujouan
authors.affiliation: Study Group on Efficiency and Quality in non-scheduled activities, Paris, France.|Hôpital Bichat-Claude Bernard, Emergency Department, Assistance Publique-Hôpitaux de Paris, Paris, France.|UA 7335 REMES, Paris Diderot University, Sorbonne Paris Cité, Paris, France.
authors.forename: Enrique
authors.initials: E
authors.lastname: Casalino
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D016001:Confidence Intervals; D003695:Delivery of Health Care / Q000458:organization & administration*; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data*; D005260:Female; D005544:Forecasting; D005602:France; D006742:Hospital Bed Capacity / Q000706:statistics & numerical data*; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D007251:Influenza, Human / Q000453:epidemiology* / Q000628:therapy; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012621:Seasons; D055815:Young Adult