title: Adding more junior residents may worsen emergency department crowding.
abstract: BACKGROUND
  Although increasing staff numbers during shifts when emergency department (ED) crowding is severe can help meet patient demand, it remains unclear how different types of added staff, particularly junior residents, may affect crowding.
  
  
  METHODS
  To identify associations between types of staff and ED crowding, we conducted a cross-sectional, single-center study in the ED of a large, teaching hospital in Japan between January and December 2012. Patients who visited the ED during the study period were enrolled. We excluded (1) patients previously scheduled to visit the ED, and (2) neonates transferred from other hospitals. During the study period, 27,970 patients were enrolled. Types of staff analyzed were junior (first and second year) residents, senior (third to fifth year) residents, attending (board-certified) physicians, and nurses. A generalized linear model was applied to length of ED stay for all patients as well as admitted and discharged patients to quantify an association with the additional staff.
  
  
  RESULTS
  In the model, addition of one attending physician or senior resident was associated with decreased length of ED stay for total patients by 3.88 or 1.64 minutes, respectively (95% CI, 2.20-5.56 and 0.81-2.48 minutes); while additional nursing staff had no association. Surprisingly, however, one additional junior resident was associated with prolonged length of ED stay for total patients by 0.97 minutes (95% CI 0.37-1.57 minutes) and for discharged patients by 1.01 minutes (95% CI 0.45-1.59 minutes).
  
  
  CONCLUSIONS
  Staffing adjustments aimed at alleviating ED crowding should focus on adding more senior staff during peak-volume shifts.
authors.affiliation: Department of Emergency Medicine, University of Fukui Hospital, Yoshida county, Fukui Prefecture, Japan.
authors.forename: Takahisa
authors.initials: T
authors.lastname: Kawano
authors.affiliation: Department of Primary Care and Emergency Medicine, Kyoto University Graduate School of Medicine, Kyoto city, Kyoto Prefecture, Japan.
authors.forename: Kei
authors.initials: K
authors.lastname: Nishiyama
authors.affiliation: Department of General Medicine, University of Fukui Hospital, Yoshida county, Fukui Prefecture, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Hayashi
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D003430:Cross-Sectional Studies; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data; D006784:Hospitals, Teaching; D006801:Humans; D007902:Length of Stay / Q000706:statistics & numerical data; D008505:Medical Staff, Hospital / Q000458:organization & administration*; D008875:Middle Aged; D015233:Models, Statistical; D010351:Patient Discharge / Q000706:statistics & numerical data; D000078329:Workforce; D055815:Young Adult