title: Impact of process improvements on measures of emergency department efficiency.
abstract: OBJECTIVE
  To study the operational impact of process improvements on emergency department (ED) patient flow. The changes did not require any increase in resources or expenditures.
  
  
  METHODS
  This was a 36-month pre- and post-intervention study to evaluate the effect of implementing process improvements at a community ED from January 2010 to December 2012. The intervention comprised streamlining triage by having patients accepted into internal waiting areas immediately after triage. Within the ED, parallel processes unfolded, and there was no restriction on when registration occurred or which health care provider a patient saw first. Flexible nursing ratios allowed nursing staff to redeploy and move to areas of highest demand. Last, demand-based physician scheduling was implemented. The main outcome was length of stay (LOS). Secondary outcomes included time to physician initial assessment (PIA), left-without-being-seen (LWBS) rates, and left-against-medical-advice (LAMA) rates. Segmented regression of interrupted time series analysis was performed to quantify the impact of the intervention, and whether it was sustained.
  
  
  RESULTS
  Patients totalling 251,899 attended the ED during the study period. Daily patient volumes increased 17.3% during the post-intervention period. Post-intervention, mean LOS decreased by 0.64 hours (p<0.005). LOS for non-admitted Canadian Triage and Acuity Scale 2 (-0.58 hours, p<0.005), 3 (-0.75 hours, p<0.005), and 4 (-0.32 hours, p<0.005) patients also decreased. There were reductions in PIA (43.81 minutes, p<0.005), LWBS (35.2%, p<0.005), and LAMA (61.9%, p<0.005).
  
  
  CONCLUSIONS
  A combination of process improvements in the ED was associated with clinically significant reductions in LOS, PIA, LWBS, and LAMA for non-resuscitative patients.
authors.affiliation: *Department of Family Medicine,Queen's University,Kingston,ON.
authors.forename: Alexander K
authors.initials: AK
authors.lastname: Leung
authors.affiliation: †Southlake Regional Health Centre,Emergency Services Program,Newmarket,ON.
authors.forename: Shawn D
authors.initials: SD
authors.lastname: Whatley
authors.affiliation: ‡Department of Statistics,University of Toronto,Toronto,ON.
authors.forename: Dechang
authors.initials: D
authors.lastname: Gao
authors.affiliation: †Southlake Regional Health Centre,Emergency Services Program,Newmarket,ON.
authors.forename: Marko
authors.initials: M
authors.lastname: Duic
mesh_terms: D000328:Adult; D017598:Efficiency, Organizational; D004636:Emergency Service, Hospital / Q000592:standards*; D005260:Female; D006801:Humans; D008297:Male; D010561:Personnel Staffing and Scheduling; D017064:Process Assessment, Health Care; D058996:Quality Improvement; D014218:Triage
keywords: efficiency; length of stay; patient flow