title: Variation in emergency department diagnostic testing and disposition outcomes in pneumonia.
abstract: OBJECTIVE
  To describe the variability across hospitals in diagnostic test utilization for children diagnosed with community-acquired pneumonia (CAP) during emergency department (ED) evaluation and to determine if test utilization is associated with hospitalization and ED revisits.
  
  
  METHODS
  We conducted a retrospective cohort study of children aged 2 months to 18 years with ED visits resulting in CAP diagnoses from 2007 to 2010 who were seen at 36 hospitals contributing data to the Pediatric Health Information System. Children with complex chronic conditions, recent hospitalization, trauma, aspiration, or perinatal infection were excluded. Primary outcomes included diagnostic testing, hospitalization, and 3-day ED revisit rates across hospitals. We examined variation in diagnostic testing among hospitals by using multivariable mixed-effects logistic regression.
  
  
  RESULTS
  A total of 100,615 ED visits were analyzed. Complete blood count (median: 28.7%), blood culture (27.9%), and chest radiograph (75.7%) were the most commonly ordered ED diagnostic tests. After adjustment for patient characteristics, significant variation (P < .001) was found for each test examined across hospitals. High test-utilizing hospitals had increased odds of hospitalization compared with low-utilizing hospitals (odds ratio: 1.86 [95% confidence interval: 1.17-2.94]; P = .008). However, differences in the odds of ED revisit between the low- and high-utilizing hospitals were not significant (odds ratio: 1.21 [95% confidence interval: 0.97-1.51]; P = .09).
  
  
  CONCLUSIONS
  Emergency departments that use more testing in diagnosing CAP have higher hospitalization rates than lower-utilizing EDs. However, ED revisit rates were not significantly different between high- and low-utilizing EDs. These results suggest an opportunity to reduce diagnostic testing for CAP without negatively affecting outcomes.
authors.affiliation: Division of Emergency Medicine, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio 45229, USA. todd.florin@cchmc.org.
authors.forename: Todd A
authors.initials: TA
authors.lastname: Florin
authors.forename: Benjamin
authors.initials: B
authors.lastname: French
authors.forename: Joseph J
authors.initials: JJ
authors.lastname: Zorc
authors.forename: Elizabeth R
authors.initials: ER
authors.lastname: Alpern
authors.forename: Samir S
authors.initials: SS
authors.lastname: Shah
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D017714:Community-Acquired Infections / Q000175:diagnosis* / Q000453:epidemiology*; D003955:Diagnostic Tests, Routine / Q000191:economics* / Q000706:statistics & numerical data*; D004636:Emergency Service, Hospital / Q000191:economics* / Q000706:statistics & numerical data*; D005260:Female; D006302:Health Services Research; D006760:Hospitalization / Q000191:economics / Q000706:statistics & numerical data; D006801:Humans; D007615:Kansas; D008297:Male; D016017:Odds Ratio; D010359:Patient Readmission / Q000191:economics / Q000706:statistics & numerical data; D011014:Pneumonia / Q000175:diagnosis* / Q000453:epidemiology*; D012189:Retrospective Studies; D014600:Utilization Review
keywords: children; clinical practice variation; diagnostic tests; emergency medicine; health resources; health services research; hospitalization; logistic models; physician practice patterns; pneumonia; radiography; utilization