title: A New Method to Classify Injury Severity by Diagnosis: Validation Using Workers' Compensation and Trauma Registry Data.
abstract: OBJECTIVE
  Acute work-related trauma is a leading cause of death and disability among U.S. workers. Existing methods to estimate injury severity have important limitations. This study assessed a severe injury indicator constructed from a list of severe traumatic injury diagnosis codes previously developed for surveillance purposes. Study objectives were to: (1) describe the degree to which the severe injury indicator predicts work disability and medical cost outcomes; (2) assess whether this indicator adequately substitutes for estimating Abbreviated Injury Scale (AIS)-based injury severity from workers' compensation (WC) billing data; and (3) assess concordance between indicators constructed from Washington State Trauma Registry (WTR) and WC data.
  
  
  METHODS
  WC claims for workers injured in Washington State from 1998 to 2008 were linked to WTR records. Competing risks survival analysis was used to model work disability outcomes. Adjusted total medical costs were modeled using linear regression. Information content of the severe injury indicator and AIS-based injury severity measures were compared using Akaike Information Criterion and R(2).
  
  
  RESULTS
  Of 208,522 eligible WC claims, 5 % were classified as severe. Among WC claims linked to the WTR, there was substantial agreement between WC-based and WTR-based indicators (kappa = 0.75). Information content of the severe injury indicator was similar to some AIS-based measures. The severe injury indicator was a significant predictor of WTR inclusion, early hospitalization, compensated time loss, total permanent disability, and total medical costs.
  
  
  CONCLUSIONS
  Severe traumatic injuries can be directly identified when diagnosis codes are available. This method provides a simple and transparent alternative to AIS-based injury severity estimation.
authors.affiliation: Department of Health Services, School of Public Health, University of Washington, Box 357660, Seattle, WA, 98195, USA. jeannes@uw.edu.|Institute for Work and Health, Toronto, ON, Canada. jeannes@uw.edu.
authors.forename: Jeanne M
authors.initials: JM
authors.lastname: Sears
authors.affiliation: Department of Health Policy and Management, Fay W. Boozman College of Public Health, University of Arkansas for Medical Sciences, Little Rock, AR, USA.|Center for Injury Research and Policy, Department of Health Policy and Management, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA.
authors.forename: Stephen M
authors.initials: SM
authors.lastname: Bowman
authors.affiliation: Trauma Clinical Consultant, Lacey, WA, USA.
authors.forename: Mary
authors.initials: M
authors.lastname: Rotert
authors.affiliation: Institute for Work and Health, Toronto, ON, Canada.|Dalla Lana School of Public Health, University of Toronto, Toronto, ON, Canada.
authors.forename: Sheilah
authors.initials: S
authors.lastname: Hogg-Johnson
mesh_terms: D015998:Abbreviated Injury Scale; D000293:Adolescent; D000328:Adult; D000368:Aged; D017048:Health Care Costs; D006760:Hospitalization; D006801:Humans; D038801:International Classification of Diseases; D008875:Middle Aged; D015233:Models, Statistical; D060051:Occupational Injuries / Q000145:classification* / Q000175:diagnosis / Q000191:economics; D012042:Registries / Q000706:statistics & numerical data*; D016019:Survival Analysis; D015599:Trauma Severity Indices; D014861:Washington; D014938:Work Capacity Evaluation; D014942:Workers' Compensation / Q000706:statistics & numerical data*; D055815:Young Adult
keywords: ICD-9-CM; ICDPIC; Injury severity; Occupational injuries; Trauma severity indices; Work disability; Workers’ compensation