title: Patient and institutional characteristics associated with initial computerized tomography in children presenting to the emergency department with kidney stones.
abstract: OBJECTIVE
  Professional associations recommend ultrasound as the initial imaging study in children with suspected nephrolithiasis but computerized tomography remains frequently used. We identified patient and institutional characteristics associated with computerized tomography as the first imaging study in children with nephrolithiasis diagnosed in the emergency department.
  
  
  METHODS
  We performed a cross-sectional study of children 2 to 18 years old with nephrolithiasis who were referred to a freestanding pediatric hospital from 2003 to 2012. We identified the imaging modality first used to evaluate the child. Medical directors at the emergency department where children were first evaluated were sent a questionnaire to ascertain emergency department characteristics. Multivariate hierarchical logistic regression models were used to determine patient and institutional characteristics associated with initial computerized tomography.
  
  
  RESULTS
  Of 536 eligible children 323 (60.2%) were evaluated at emergency departments from which surveys were returned. Of the 323 children 238 (71%) underwent computerized tomography as initial imaging. Ultrasound was available at all emergency departments. Older patient age was associated with higher initial computerized tomography use (OR 1.09, 95% CI 1.04-1.16). A more recent year of diagnosis (OR 0.80, 95% CI 0.72-0.88) and a clinical care pathway that used ultrasound as initial imaging (OR 0.29, 95% CI 0.01-0.38) were associated with lower initial computerized tomography use.
  
  
  CONCLUSIONS
  A clinical care pathway in the emergency department was the only institutional characteristic associated with lower computerized tomography use. Future studies are needed to determine whether care pathways using ultrasound for initial imaging in children with suspected nephrolithiasis would decrease inappropriate computerized tomography and improve adherence to national guidelines.
authors.affiliation: Division of Urology, Department of Surgery, The Perelman School of Medicine at University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: Justin B
authors.initials: JB
authors.lastname: Ziemba
authors.affiliation: Division of Urology, Department of Surgery, The Perelman School of Medicine at University of Pennsylvania, Philadelphia, Pennsylvania; Division of Urology, Department of Surgery, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania.
authors.forename: Douglas A
authors.initials: DA
authors.lastname: Canning
authors.affiliation: Department of Emergency Medicine, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania.
authors.forename: Jane
authors.initials: J
authors.lastname: Lavelle
authors.affiliation: Division of Urology, Department of Surgery, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania.
authors.forename: Angela
authors.initials: A
authors.lastname: Kalmus
authors.affiliation: Division of Urology, Department of Surgery, The Perelman School of Medicine at University of Pennsylvania, Philadelphia, Pennsylvania; Division of Urology, Department of Surgery, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania; Center for Pediatric Clinical Effectiveness, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania. Electronic address: tasiang@chop.edu.
authors.forename: Gregory E
authors.initials: GE
authors.lastname: Tasian
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D004636:Emergency Service, Hospital; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D053040:Nephrolithiasis / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed; D014463:Ultrasonography
keywords: emergency service; hospital; kidney; nephrolithiasis; tomography; ultrasonography; x-ray computed