title: No diversion in Western Massachusetts.
abstract: BACKGROUND
  Massachusetts (MA) instituted a moratorium on ambulance diversion ("No Diversion") on January 1, 2009.
  
  
  OBJECTIVE
  Determine whether No Diversion was associated with changes in Emergency Department (ED) throughput measures.
  
  
  METHODS
  Comparison of three 3-month periods. Period 1: 1 year prior (January-March 2008); Period 2: 3 months prior (October-December 2008); Period 3: 3 months after (January-March 2009).
  
  
  METHODS
  Seven EDs in Western MA; two - including the only Level I Trauma Center - were "high" diversion (≥562 h/year) and 5 were "low" diversion (≤260 h/year). For "all," "high" diversion and "low" diversion ED groups, we compared mean monthly throughput measures, including: 1) total volume, 2) number of admissions, 3) number of elopements, 4) length of stay for all, admitted and discharged patients. Mean absolute and percent changes were estimated using mixed-effects regression analysis. Linear mixed models were run for "all," "high" and "low" diversion EDs comparing means of changes between periods. Results are presented as mean change per month in number and percent, and 95% confidence intervals were calculated. We specified that a clinically significant effect of No Diversion had to meet two criteria: 1) there was a consistent difference in the means for both the Period 1 vs. Period 3 comparison and the Period 2 vs. Period 3 comparison, and 2) both comparisons had to achieve statistical significance at p ≤ 0.01.
  
  
  RESULTS
  According to pre-determined criteria, no clinically significant changes were found in any ED group in mean monthly volume, admissions, elopements, or length-of-stay for any patient disposition group.
  
  
  CONCLUSIONS
  No Diversion was not associated with significant changes in throughput measures in "all," "high" diversion and "low" diversion EDs.
authors.affiliation: Department of Emergency Medicine, Baystate Medical Center and Tufts University School of Medicine, Springfield, Massachusetts, USA.
authors.forename: Niels K
authors.initials: NK
authors.lastname: Rathlev
authors.forename: Fidela
authors.initials: F
authors.lastname: Blank
authors.forename: Ben
authors.initials: B
authors.lastname: Osborne
authors.forename: Adam
authors.initials: A
authors.lastname: Kellogg
authors.forename: Haiping
authors.initials: H
authors.lastname: Li
authors.forename: Jacques
authors.initials: J
authors.lastname: Blanchet
authors.forename: Ray F
authors.initials: RF
authors.lastname: Conway
authors.forename: Louis
authors.initials: L
authors.lastname: Durkin
authors.forename: Rick
authors.initials: R
authors.lastname: Gerstein
authors.forename: Stan
authors.initials: S
authors.lastname: Strzempko
authors.forename: Manish
authors.initials: M
authors.lastname: Vig
authors.forename: John P
authors.initials: JP
authors.lastname: Santoro
authors.forename: Paul
authors.initials: P
authors.lastname: Visintainer
mesh_terms: D000552:Ambulances / Q000706:statistics & numerical data*; D001509:Bed Occupancy; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data*; D006291:Health Policy; D006801:Humans; D007902:Length of Stay / Q000706:statistics & numerical data; D016014:Linear Models; D008404:Massachusetts; D010343:Patient Admission / Q000706:statistics & numerical data*; D010360:Patient Transfer / Q000706:statistics & numerical data*; D012189:Retrospective Studies; D013219:State Government