title: The Association Between Use of Brain CT for Atraumatic Headache and 30-Day Emergency Department Revisitation.
abstract: OBJECTIVE
  The purpose of this article is to describe the association between initial CT for atraumatic headache and repeat emergency department (ED) visitation within 30 days of ED discharge.
  
  
  METHODS
  A retrospective observational study was performed at an academic urban ED with more than 85,000 annual visits. All adult patients with a chief complaint of headache from January through December 2010 who were discharged after ED evaluation were included in the analysis. Patients were excluded if they were transferred, died in the ED, or had a diagnosis indicating a traumatic mechanism. A propensity score-matched logistic regression model was used to determine whether the use of brain CT was associated with the primary outcome of ED revisitation within 30 days, controlling for potential confounding variables.
  
  
  RESULTS
  Of 80,619 total patient visits to the ED during the study period, 922 ED discharges with a chief complaint of headache were included. A total of 139 (15.1%) patients revisited within 30 days. The return rate was 11.2% among patients who underwent CT at their initial visit and 21.1% among those who did not. In the adjusted analysis, controlling for age, race, sex, insurance status, triage vital signs, laboratory values, and triage pain level, the odds ratio for revisitation given CT performance was 0.49 (95% CI, 0.27-0.86).
  
  
  CONCLUSIONS
  After adjustment for clinical factors, we found that patients who underwent a brain CT examination for atraumatic headache at an initial ED visit were less likely to return to the ED within 30 days. Future appropriate use quality metrics regarding ED imaging use may need to incorporate downstream health care use.
authors: 1 BerbeeWalsh Department of Emergency Medicine, University of Wisconsin-Madison School of Medicine and Public Health, 800 University Bay Dr, Ste 310, Mail Code 9123, Madison, WI 53705.
authors: Brian W
authors: BW
authors: Patterson
authors: 2 Department of Emergency Medicine, Indiana University School of Medicine, Indianapolis, IN.
authors: Peter S
authors: PS
authors: Pang
authors: 3 Department of Emergency Medicine, Northwestern University, Chicago, IL.
authors: Lora
authors: L
authors: AlKhawam
authors: 1 BerbeeWalsh Department of Emergency Medicine, University of Wisconsin-Madison School of Medicine and Public Health, 800 University Bay Dr, Ste 310, Mail Code 9123, Madison, WI 53705.
authors: Azita G
authors: AG
authors: Hamedani
authors: 4 Department of Biostatistics and Medical Informatics, Department of Pediatrics, University of Wisconsin School of Medicine and Public Health, Madison, WI.
authors: Eneida A
authors: EA
authors: Mendonca
authors: 5 Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA.
authors: Ying-Qi
authors: YQ
authors: Zhao
authors: 6 Department of Emergency Medicine and Center for Outcomes Research and Evaluation, Yale University School of Medicine, New Haven, CT.
authors: Arjun K
authors: AK
authors: Venkatesh
mesh_terms: D000328:Adult; D001927:Brain Diseases / Q000000981:diagnostic imaging / Q000453:epidemiology; D001930:Brain Injuries; D015984:Causality; D015897:Comorbidity; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data*; D005260:Female; D006261:Headache / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000453:epidemiology*; D006801:Humans; D008297:Male; D000069342:Medical Overuse / Q000517:prevention & control / Q000706:statistics & numerical data; D010359:Patient Readmission / Q000706:statistics & numerical data*; D015995:Prevalence; D012189:Retrospective Studies; D012307:Risk Factors; D014057:Tomography, X-Ray Computed / Q000706:statistics & numerical data*; D014481:United States / Q000453:epidemiology; D014600:Utilization Review
keywords: CT brain; appropriate use; emergency; headache