title: Do delays in radiology lead to breaches in the 4-hour rule?
abstract: OBJECTIVE
  To assess trends in medical imaging requests before and after the 4-hour rule commenced and to assess the imaging time component of emergency department (ED) length of stay (LOS).
  
  
  METHODS
  Retrospective analysis of ED patients and imaging requests 1 year prior to and 3 years after implementation of the 4-hour rule (April to December for 2011-2014) was performed at a single adult tertiary referral Level 1 trauma hospital with Level 6 ED. Logistic regression was used to evaluate trends in the number of ED patient presentations, patient triage categories, and imaging requests for these patients. The imaging component of the total ED LOS was compared for patients who met the 4-hour target and patients who did not.
  
  
  RESULTS
  Compared to 2011 (before the 4-hour rule), ED presentations increased 4.74% in 2012, 12.7% in 2013, 21.28% in 2014 (p<0.01). Total imaging requests increased 23.05% in 2012, 48.04% in 2013, 60.77% in 2014 (p<0.01). For patients breaching the 4-hour rule, the mean time before radiology request was 2.4-2.8 hours; mean time from imaging request to completion was 1.2-1.3 hours; mean time from imaging completion to discharge from ED was the longest component of ED LOS (4.9-5.9 hours).
  
  
  CONCLUSIONS
  There has been a significant increase in imaging requests, with a trend towards more CT and less radiography requests. Imaging requests for patients who breached the 4-hour target were made on average 2.4-2.8 hours after triage and average time after imaging in itself, exceeded 4 hours. Imaging is not likely a causative factor for patients breaching the 4-hour target.
authors.affiliation: Department of Radiology, Westmead Hospital, Hawkesbury Rd, Westmead, NSW 2145, Australia.
authors.forename: R
authors.initials: R
authors.lastname: Tse
authors.affiliation: Department of Radiology, Westmead Hospital, Hawkesbury Rd, Westmead, NSW 2145, Australia.
authors.forename: N
authors.initials: N
authors.lastname: Thompson
authors.affiliation: Graduate School of Medicine, University of Wollongong, Northfields Ave, Wollongong, NSW 2522, Australia; Faculty of Medicine, The University of Sydney, NSW 2006, Australia. Electronic address: moscova@uow.edu.au.
authors.forename: M
authors.initials: M
authors.lastname: Moscova
authors.affiliation: School of Medicine, Western Sydney University, Campbelltown, NSW, Australia.
authors.forename: D
authors.initials: D
authors.lastname: Sindhusake
authors.affiliation: Faculty of Medicine, The University of Sydney, NSW 2006, Australia; Emergency Department, Westmead Hospital, Hawkesbury Rd, Westmead, NSW, Australia; NHMRC Centre of Excellence in Critical Infection, Westmead Millennium Institute, Westmead Hospital Emergency Department, Corner Hawkesbury and Darcy Roads, Westmead, NSW 2145, Australia.
authors.forename: A
authors.initials: A
authors.lastname: Shetty
authors.affiliation: Department of Radiology, Westmead Hospital, Hawkesbury Rd, Westmead, NSW 2145, Australia; Faculty of Medicine, The University of Sydney, NSW 2006, Australia.
authors.forename: N
authors.initials: N
authors.lastname: Young
mesh_terms: D001315:Australia / Q000453:epidemiology; D003952:Diagnostic Imaging / Q000592:standards / Q000706:statistics & numerical data*; D004636:Emergency Service, Hospital / Q000592:standards / Q000706:statistics & numerical data*; D019983:Guideline Adherence / Q000706:statistics & numerical data; D007902:Length of Stay / Q000706:statistics & numerical data*; D017410:Practice Guidelines as Topic; D011871:Radiology / Q000592:standards* / Q000706:statistics & numerical data; D012017:Referral and Consultation / Q000706:statistics & numerical data*; D014600:Utilization Review; D014850:Waiting Lists