title: Factors associated with ED length of stay during a mass casualty incident.
abstract: BACKGROUND
  The aim of this study was to examine the factors associated with emergency department (ED) length of stay (LOS) using the patient registry data from a medical burns center during a burn injury mass casualty incident (MCI) after a dust explosion in New Taipei City, Taiwan.
  
  
  METHODS
  This was a retrospective cohort study conducted at an urban, tertiary care teaching hospital during an MCI event that occurred on June 27, 2015. A celebratory party was held at the Formosa Fun Water Park in New Taipei City, Taiwan. At 20:32, the was an explosion caused by an overheated spotlight accidentally igniting colored cornstarch powder that had been sprayed on the stage. Factors associated with ED LOS were compared.
  
  
  RESULTS
  In total, 48 burn injury patients were enrolled for study analysis. The median total body surface area of second- to third-degree burns was 35.0% (interquartile range [IQR], 15.8%-55.0%). The median ED LOS was 121.5 minutes (IQR, 38.3-209.8 minutes). The output time interval accounted for the longest interval with a median time of 56.0 minutes (IQR, 15.3-117.3 minutes). In multivariate analysis of the variables, triage level (level III; hazard ratio, 0.06; 95% confidence interval, 0.01-0.52) and output time (hazard ratio, 0.97; 95% confidence interval, 0.96-0.98) were significant influential factors.
  
  
  CONCLUSIONS
  The triage level and output time intervals were significantly associated with ED LOS in a burn-related MCI. Time effectiveness analyses, using a patient flow model, might serve as an important indicator during a hospital MCI response.
authors.affiliation: Department of Emergency Medicine, Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan.
authors.forename: Shou-Yen
authors.initials: SY
authors.lastname: Chen
authors.affiliation: Department of Emergency Medicine, Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan.
authors.forename: Chung-Hsien
authors.initials: CH
authors.lastname: Chaou
authors.affiliation: Department of Emergency Medicine, Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan.
authors.forename: Chip-Jin
authors.initials: CJ
authors.lastname: Ng
authors.affiliation: Department of Plastic and Reconstructive surgery, Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan.
authors.forename: Ming-Huei
authors.initials: MH
authors.lastname: Cheng
authors.affiliation: Department of Emergency Medicine, Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan.
authors.forename: Ya-Wen
authors.initials: YW
authors.lastname: Hsiau
authors.affiliation: Department of Trauma and Emergency Surgery, Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan.
authors.forename: Shih-Ching
authors.initials: SC
authors.lastname: Kang
authors.affiliation: Department of Trauma and Emergency Surgery, Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan.
authors.forename: Chih-Po
authors.initials: CP
authors.lastname: Hsu
authors.affiliation: Department of Emergency Medicine, Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan. Electronic address: wengym33@gmail.com.
authors.forename: Yi-Ming
authors.initials: YM
authors.lastname: Weng
authors.affiliation: Department of Emergency Medicine, Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan.
authors.forename: Jih-Chang
authors.initials: JC
authors.lastname: Chen
mesh_terms: D000328:Adult; D002056:Burns / Q000453:epidemiology* / Q000628:therapy; D004636:Emergency Service, Hospital; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D007902:Length of Stay / Q000639:trends*; D008297:Male; D054527:Mass Casualty Incidents / Q000706:statistics & numerical data*; D012189:Retrospective Studies; D013624:Taiwan / Q000453:epidemiology; D013997:Time Factors; D014218:Triage; D055815:Young Adult