title: Emergency department overcrowding following systematic hospital restructuring: trends at twenty hospitals over ten years.
abstract: OBJECTIVE
  Hospital restructuring often results in fewer inpatient beds, increased ambulatory services, and closures of hospitals or emergency departments (EDs). The authors sought to determine the impact of systematic hospital restructuring on ED overcrowding.
  
  
  METHODS
  Time series analyses of average monthly overcrowding for EDs in Toronto, Ontario, Canada, from 1991 and 2000 (n = 20 hospitals, 120 months) were conducted. Autoregression models evaluated the rate of increase of overcrowding before and during systematic restructuring. A secondary analysis included total ED visits, patient age, and sex distribution as covariates. Seasonality was assessed by means of spectral analysis.
  
  
  RESULTS
  Severe and moderate overcrowding averaged 3% and 14% of the time each month, respectively, over the whole period. Before restructuring (n = 74 months), severe and moderate overcrowding averaged 0.5% and 9% per month, respectively; during restructuring (n = 46 months), the monthly averages were 6% and 23%, respectively. Neither severe nor moderate overcrowding was increasing before restructuring. During restructuring, however, both increased significantly (severe 0.2% per month [p < 0.0001]; moderate 0.5% per month [p < 0.0001]). Similar results were found after controlling for ED utilization. Female gender independently predicted increased overcrowding; older age predicted reduced moderate overcrowding; number of total visits was not a predictor. Spectral analysis revealed significant seasonality in overcrowding.
  
  
  CONCLUSIONS
  Hospital restructuring was associated with increased ED overcrowding, even after controlling for utilization and patient demographics. Restructuring should proceed slowly to allow time for monitoring of its effects and modification of the process, because the impact of incremental reductions in hospital resources may be magnified as maximum operating capacity is approached.
authors.affiliation: Department of Emergency Services, Clinical Epidemiology Unit, and Division of Pre-Hospital Care Research Program, Sunnybrook and Women's College Health Sciences Centre, Toronto, Ontario, Canada. mjs@ices.on.ca
authors.forename: M J
authors.initials: MJ
authors.lastname: Schull
authors.forename: J P
authors.initials: JP
authors.lastname: Szalai
authors.forename: B
authors.initials: B
authors.lastname: Schwartz
authors.forename: D A
authors.initials: DA
authors.lastname: Redelmeier
mesh_terms: D000328:Adult; D000367:Age Factors; D003441:Crowding; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data / Q000639:trends; D005260:Female; D006754:Hospital Restructuring / Q000639:trends; D006786:Hospitals, Urban / Q000639:trends; D006801:Humans; D008297:Male; D009864:Ontario / Q000453:epidemiology; D011237:Predictive Value of Tests; D012621:Seasons; D012737:Sex Factors; D013997:Time Factors; D014504:Urban Health