title: Identifying patients with severe sepsis using administrative claims: patient-level validation of the angus implementation of the international consensus conference definition of severe sepsis.
abstract: BACKGROUND
  Severe sepsis is a common and costly problem. Although consistently defined clinically by consensus conference since 1991, there have been several different implementations of the severe sepsis definition using ICD-9-CM codes for research. We conducted a single center, patient-level validation of 1 common implementation of the severe sepsis definition, the so-called "Angus" implementation.
  
  
  METHODS
  Administrative claims for all hospitalizations for patients initially admitted to general medical services from an academic medical center in 2009-2010 were reviewed. On the basis of ICD-9-CM codes, hospitalizations were sampled for review by 3 internal medicine-trained hospitalists. Chart reviews were conducted with a structured instrument, and the gold standard was the hospitalists' summary clinical judgment on whether the patient had severe sepsis.
  
  
  RESULTS
  Three thousand one hundred forty-six (13.5%) hospitalizations met ICD-9-CM criteria for severe sepsis by the Angus implementation (Angus-positive) and 20,142 (86.5%) were Angus-negative. Chart reviews were performed for 92 randomly selected Angus-positive and 19 randomly-selected Angus-negative hospitalizations. Reviewers had a κ of 0.70. The Angus implementation's positive predictive value was 70.7% [95% confidence interval (CI): 51.2%, 90.5%]. The negative predictive value was 91.5% (95% CI: 79.0%, 100%). The sensitivity was 50.4% (95% CI: 14.8%, 85.7%). Specificity was 96.3% (95% CI: 92.4%, 100%). Two alternative ICD-9-CM implementations had high positive predictive values but sensitivities of <20%.
  
  
  CONCLUSIONS
  The Angus implementation of the international consensus conference definition of severe sepsis offers a reasonable but imperfect approach to identifying patients with severe sepsis when compared with a gold standard of structured review of the medical chart by trained hospitalists.
authors.affiliation: *Department of Medicine, University of Michigan †VA Center for Clinical Management Research ‡VA Geriatrics Research, Education and Clinical Center, Ann Arbor, MI.
authors.forename: Theodore J
authors.initials: TJ
authors.lastname: Iwashyna
authors.forename: Andrew
authors.initials: A
authors.lastname: Odden
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Rohde
authors.forename: Catherine
authors.initials: C
authors.lastname: Bonham
authors.forename: Latoya
authors.initials: L
authors.lastname: Kuhn
authors.forename: Preeti
authors.initials: P
authors.lastname: Malani
authors.forename: Lena
authors.initials: L
authors.lastname: Chen
authors.forename: Scott
authors.initials: S
authors.lastname: Flanders
mesh_terms: D000046:Academic Medical Centers / Q000706:statistics & numerical data; D000328:Adult; D000368:Aged; D000465:Algorithms; D003937:Diagnosis, Differential; D005260:Female; D019983:Guideline Adherence; D006284:Health Plan Implementation / Q000706:statistics & numerical data*; D006305:Health Status Indicators; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D007345:Insurance Claim Review / Q000706:statistics & numerical data*; D038801:International Classification of Diseases; D008297:Male; D006278:Medicare; D008875:Middle Aged; D009102:Multiple Organ Failure / Q000145:classification / Q000175:diagnosis; D018805:Sepsis / Q000145:classification / Q000175:diagnosis*; D012772:Shock, Septic / Q000145:classification / Q000175:diagnosis*; D014481:United States