title: Association between ED crowding and delay in resuscitation effort.
abstract: OBJECTIVE
  Few investigations have been performed that address why emergency department (ED) crowding is associated with an increase in hospital mortality for emergency patients. The purpose of this study was to evaluate whether ED crowding is associated with delayed resuscitation efforts (DREs) that resulted in hospital mortality.
  
  
  METHODS
  This is a retrospective observational study performed at a single urban tertiary ED. All adult patients who entered the resuscitation room and underwent resuscitative procedures from October 2008 to May 2010 were enrolled in the study. Demographic data were collected from a designed resuscitation room registry. The ED electronic log data were used for calculating the crowding status. A crowded day was defined as a daily number of patients greater than 93, which was a cut-off derived from a sensitivity analysis. The primary outcome was a DRE, which occurred when a patient was located in the hallway or waiting room, then entered the resuscitation room, and received resuscitative procedures after the patient had clinically deteriorated. A secondary outcome was hospital mortality. Matched samples were selected using propensity scores to consider the clinical parameters and emergency severity index when the patients received triage immediately after registration. A logistic regression analysis was modeled to estimate the odds ratios (ORs) with 95% confidence intervals (CIs) on the DRE.
  
  
  RESULTS
  A total of 1296 patients underwent resuscitative procedures in the resuscitation room. Of these, 226 (17.4%) were classified as the DRE group. A final 396 cases (30.6%) were matched and analyzed between DRE and non-DRE using the propensity score. The incidence of DRE was significantly higher on crowded days (OR, 2.00; 95% CI, 1.28-3.15). Mortality during the ED stay or during the total hospital stay was significantly higher in the DRE group (OR, 3.39; 95% CI, 1.22-9.45 and OR, 3.96; 95% CI, 2.28-6.88, respectively) compared with the non-DRE group.
  
  
  CONCLUSIONS
  Delays in resuscitation efforts occurred more frequently on crowded days and were associated with higher in-hospital mortality.
authors.affiliation: Department of Emergency Medicine, Seoul National University Boramae Medical Center, Seoul, South Korea. emkjhong@gmail.com
authors.forename: Ki Jeong
authors.initials: KJ
authors.lastname: Hong
authors.forename: Sang Do
authors.initials: SD
authors.lastname: Shin
authors.forename: Kyoung Jun
authors.initials: KJ
authors.lastname: Song
authors.forename: Won Chul
authors.initials: WC
authors.lastname: Cha
authors.forename: Jin Seong
authors.initials: JS
authors.lastname: Cho
mesh_terms: D000328:Adult; D000368:Aged; D003441:Crowding; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data*; D005260:Female; D006272:Health Facility Environment / Q000706:statistics & numerical data*; D017052:Hospital Mortality; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D057216:Propensity Score; D012372:ROC Curve; D012042:Registries; D012151:Resuscitation / Q000401:mortality / Q000706:statistics & numerical data*; D012189:Retrospective Studies; D020379:Risk Adjustment; D012720:Severity of Illness Index; D013997:Time Factors