title: Validation of ICDPIC software injury severity scores using a large regional trauma registry.
abstract: BACKGROUND
  Administrative or quality improvement registries may or may not contain the elements needed for investigations by trauma researchers. International Classification of Diseases Program for Injury Categorisation (ICDPIC), a statistical program available through Stata, is a powerful tool that can extract injury severity scores from ICD-9-CM codes. We conducted a validation study for use of the ICDPIC in trauma research.
  
  
  METHODS
  We conducted a retrospective cohort validation study of 40,418 patients with injury using a large regional trauma registry. ICDPIC-generated AIS scores for each body region were compared with trauma registry AIS scores (gold standard) in adult and paediatric populations. A separate analysis was conducted among patients with traumatic brain injury (TBI) comparing the ICDPIC tool with ICD-9-CM embedded severity codes. Performance in characterising overall injury severity, by the ISS, was also assessed.
  
  
  RESULTS
  The ICDPIC tool generated substantial correlations in thoracic and abdominal trauma (weighted κ 0.87-0.92), and in head and neck trauma (weighted κ 0.76-0.83). The ICDPIC tool captured TBI severity better than ICD-9-CM code embedded severity and offered the advantage of generating a severity value for every patient (rather than having missing data). Its ability to produce an accurate severity score was consistent within each body region as well as overall.
  
  
  CONCLUSIONS
  The ICDPIC tool performs well in classifying injury severity and is superior to ICD-9-CM embedded severity for TBI. Use of ICDPIC demonstrates substantial efficiency and may be a preferred tool in determining injury severity for large trauma datasets, provided researchers understand its limitations and take caution when examining smaller trauma datasets.
authors.affiliation: Department of Anesthesiology and Pediatrics, School of Medicine, Duke University, Durham, North Carolina, USA.
authors.forename: Nathaniel H
authors.initials: NH
authors.lastname: Greene
authors.affiliation: Department of Epidemiology, School of Public Health, University of Washington, Seattle, Washington, USA.
authors.forename: Mary A
authors.initials: MA
authors.lastname: Kernic
authors.affiliation: Department of Anesthesiology and Pain Medicine, School of Medicine, University of Washington, Seattle, Washington, USA Department of Pediatrics, School of Medicine, University of Washington, Seattle, Washington, USA Harborview Injury Prevention and Research Center, Harborview Medical Center, Seattle, Washington, USA.
authors.forename: Monica S
authors.initials: MS
authors.lastname: Vavilala
authors.affiliation: Department of Epidemiology, School of Public Health, University of Washington, Seattle, Washington, USA Department of Pediatrics, School of Medicine, University of Washington, Seattle, Washington, USA Harborview Injury Prevention and Research Center, Harborview Medical Center, Seattle, Washington, USA.
authors.forename: Frederick P
authors.initials: FP
authors.lastname: Rivara
mesh_terms: D015998:Abbreviated Injury Scale; D019540:Area Under Curve; D005260:Female; D005568:Forms and Records Control / Q000458:organization & administration; D006801:Humans; D015601:Injury Severity Score; D038801:International Classification of Diseases; D008297:Male; D017063:Outcome Assessment, Health Care; D058996:Quality Improvement / Q000592:standards*; D012042:Registries; D012189:Retrospective Studies; D012984:Software; D014947:Wounds and Injuries / Q000145:classification / Q000175:diagnosis* / Q000401:mortality
keywords: Injury Diagnosis