title: Influence of CT utilisation on patient flow in the emergency department: a retrospective 1-year cohort study.
abstract: CT, an important diagnostic tool in the emergency department (ED), might increase the ED length of stay (LOS). Considering the issue of ED overcrowding, it is important to evaluate whether CT use delays or facilitates patient disposition in the ED.
  
  
  
  A retrospective 1-year cohort study.
  
  
  
  5 EDs within the same healthcare system dispersed nationwide in Taiwan.
  
  
  
  All adult non-trauma patients who visited the 5 EDs from 1 July 2011 to 30 June 2012.
  
  
  
  Patients were grouped by whether or not they underwent a CT scan (CT and non-CT groups, respectively).
  
  
  
  The ED LOS and hospital LOS between patients who had and had not undergone CT scans were compared by stratifying different dispositions and diagnoses.
  
  
  
  CT use prolonged patient ED LOS among those who were directly discharged from the ED. Among patients admitted to the observation unit and then discharged, patients diagnosed with nervous system disease had shorter ED LOS if they underwent a CT scan. CT use facilitated patient admission to the general ward. CT use also accelerated patients' admission to the intensive care unit (ICU) for patients with nervous system disease, neoplasm and digestive disease. Finally, patients admitted to the general wards had shorter hospital LOS if they underwent CT scans in the ED.
  
  
  
  CT use did not seem to have delayed patient disposition in ED. While CT use facilitated patient disposition if they were finally hospitalised, it mildly prolonged ED LOS in cases of patients discharged from the ED.
authors.affiliation: Department of Emergency Medicine, Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Kaohsiung, Taiwan Department of Public Health, College of Health Science, Kaohsiung Medical University, Kaohsiung, Taiwan.
authors.forename: Chao-Jui
authors.initials: CJ
authors.lastname: Li
authors.affiliation: Department of Anesthesiology, Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Kaohsiung, Taiwan.
authors.forename: Yuan-Jhen
authors.initials: YJ
authors.lastname: Syue
authors.affiliation: Department of Emergency Medicine, Changhua Christian Hospital, Changhua, Taiwan School of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.
authors.forename: Yan-Ren
authors.initials: YR
authors.lastname: Lin
authors.affiliation: Department of Emergency Medicine, Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Kaohsiung, Taiwan.
authors.forename: Hsien-Hung
authors.initials: HH
authors.lastname: Cheng
authors.affiliation: Department of Emergency Medicine, Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Kaohsiung, Taiwan.
authors.forename: Fu-Jen
authors.initials: FJ
authors.lastname: Cheng
authors.affiliation: Department of Emergency Medicine, Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Kaohsiung, Taiwan.
authors.forename: Tsung-Cheng
authors.initials: TC
authors.lastname: Tsai
authors.affiliation: Department of Emergency Medicine, Chang Gung Memorial Hospital, Keelung, Taiwan Community Medicine Research Center, Chang Gung Memorial Hospital, Keelung, Taiwan Clinical Informatics and Medical Statistics Research Center, Chang Gung University, Taoyuan, Taiwan.
authors.forename: Kuan-Fu
authors.initials: KF
authors.lastname: Chen
authors.affiliation: Department of Public Health, College of Health Science, Kaohsiung Medical University, Kaohsiung, Taiwan Research Center for Environmental Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.
authors.forename: Chien-Hung
authors.initials: CH
authors.lastname: Lee
mesh_terms: D003441:Crowding; D017598:Efficiency, Organizational / Q000592:standards*; D004636:Emergency Service, Hospital / Q000458:organization & administration*; D005260:Female; D006801:Humans; D007902:Length of Stay / Q000706:statistics & numerical data; D008297:Male; D008875:Middle Aged; D010043:Outcome and Process Assessment, Health Care; D010360:Patient Transfer; D012189:Retrospective Studies; D013624:Taiwan / Q000453:epidemiology; D013997:Time Factors; D014057:Tomography, X-Ray Computed / Q000706:statistics & numerical data*
keywords: emergency department; length of stay; patient flow