title: Developing a diagnosis-based severity classification system for use in emergency medical services for children.
abstract: OBJECTIVE
  Lack of adequate risk adjustment methodologies has hindered the progress of emergency medicine health services research. The authors hypothesized that a consensus-derived, diagnosis-based severity classification system (SCS) would be significantly associated with actual measures of emergency department (ED) resource use and could ultimately be used to examine severity-adjusted outcomes across patient populations.
  
  
  METHODS
  A panel of subject matter experts used consensus methods to assign severity scores (1 = lowest severity to 5 = highest severity) to 3,041 ED International Classifications of Diseases (ICD), 9th revision, diagnosis codes. SCS scores were assigned to ED visits using the visit diagnosis code with the highest severity. We tested the association between the SCS scores and measures of ED resource use in three data sets: the Pediatric Emergency Care Applied Research Network Core Data Project (PCDP), the National Hospital Ambulatory Medical Care Survey (NHAMCS), and the Connecticut state ED data set.
  
  
  RESULTS
  There was a significant association between the five-level SCS and all six measures of resource use: triage category, disposition, ED resource use, Current Procedural Terminology Evaluation and Management (CPT E&M) codes, ED length of stay, and ED charges within the three ED data sets.
  
  
  CONCLUSIONS
  The SCS demonstrates validity in its strong association with actual ED resource use. The use of readily available ICD-9 diagnosis codes makes the SCS useful as a risk adjustment tool for health services research.
authors.affiliation: Department of Pediatrics, University of Cincinnati College of Medicine, James M. Anderson Center for Health Systems Excellence and Division of Emergency Medicine, Cincinnati Children's Hospital and Medical Center, Cincinnati, OH, USA. evaline.alessandrini@cchmc.org
authors.forename: Evaline A
authors.initials: EA
authors.lastname: Alessandrini
authors.forename: Elizabeth R
authors.initials: ER
authors.lastname: Alpern
authors.forename: James M
authors.initials: JM
authors.lastname: Chamberlain
authors.forename: Judy A
authors.initials: JA
authors.lastname: Shea
authors.forename: Richard
authors.initials: R
authors.lastname: Holubkov
authors.forename: Marc H
authors.initials: MH
authors.lastname: Gorelick
mesh_terms: D000293:Adolescent; D016009:Chi-Square Distribution; D002648:Child; D039702:Current Procedural Terminology; D003697:Delphi Technique; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data*; D005260:Female; D006302:Health Services Research; D006801:Humans; D038801:International Classification of Diseases / Q000706:statistics & numerical data*; D008297:Male; D012720:Severity of Illness Index; D014218:Triage