title: Assessing the use of international classification of diseases-10th revision codes from the emergency department for the identification of acute heart failure.
abstract: OBJECTIVE
  The objective of this study was to compare administrative codes with chart review for patients with acute heart failure (AHF).
  
  
  BACKGROUND
  Administrative databases are used in population health research; however, the validity of codes in the emergency department (ED) for AHF compared with chart review is uncertain.
  
  
  METHODS
  A cohort of 952 patients with suspected AHF were prospectively recruited from 4 EDs in Edmonton, Alberta, Canada, from 2009 to 2012. Patients had their diagnoses adjudicated by expert physicians using a standardized scoring system and detailed chart review. ED and hospital discharge International Classification of Diseases-10th Revision (ICD-10) codes were captured in the main diagnosis or in any diagnostic field.
  
  
  RESULTS
  The 897 patients had a median age of 77 years (interquartile range: 67 to 85 years), and 806 (90%) were admitted to the hospital. Overall, 809 patients (90.2%) had AHF by adjudication and 660 (73.6%) had ICD-10 code I50.x as a main diagnosis in the ED administrative data, respectively. The positive predictive value of an AHF main diagnosis in the ED administrative data was 93.3% (95% confidence interval [CI]: 92.0% to 94.7%), with sensitivity of 76.1% (95% CI: 75.0% to 77.2%) and specificity of 50.0% (95% CI: 39.8% to 60.1%). The positive predictive value for AHF in any diagnostic field of the ED administrative data was 92.0% (95% CI: 91.1% to 93.0%), with a sensitivity of 89.4% (95% CI: 88.5% to 90.4%) and specificity of 28.4% (95% CI: 20.1% to 37.9%).
  
  
  CONCLUSIONS
  An ICD-10 I50.x diagnosis in the ED is highly predictive of AHF compared with chart-level adjudication using a validated score. Thus, the use of these codes in ED administrative databases could identify AHF for clinical and epidemiological studies.
authors.affiliation: Department of Medicine, University of Alberta, Alberta, Canada.
authors.forename: Natalia
authors.initials: N
authors.lastname: Frolova
authors.affiliation: Patient Health Outcomes Research and Clinical Effectiveness Unit, Division of General Internal Medicine, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Bakal
authors.affiliation: Patient Health Outcomes Research and Clinical Effectiveness Unit, Division of General Internal Medicine, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Finlay A
authors.initials: FA
authors.lastname: McAlister
authors.affiliation: Department of Emergency Medicine, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Brian H
authors.initials: BH
authors.lastname: Rowe
authors.affiliation: Institute for Public Health, University of Calgary, Calgary, Alberta, Canada.
authors.forename: Hude
authors.initials: H
authors.lastname: Quan
authors.affiliation: Division of Cardiology, Department of Medicine, University of Alberta, Alberta, Canada.
authors.forename: Padma
authors.initials: P
authors.lastname: Kaul
authors.affiliation: Division of Cardiology, Department of Medicine, University of Alberta, Alberta, Canada; Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, Alberta, Canada. Electronic address: jae2@ualberta.ca.
authors.forename: Justin A
authors.initials: JA
authors.lastname: Ezekowitz
mesh_terms: D000208:Acute Disease; D000368:Aged; D000369:Aged, 80 and over; D000416:Alberta / Q000453:epidemiology; D016208:Databases, Factual; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data; D005260:Female; D006333:Heart Failure / Q000145:classification* / Q000453:epidemiology; D006801:Humans; D015994:Incidence; D038801:International Classification of Diseases / Q000706:statistics & numerical data*; D008297:Male; D015203:Reproducibility of Results; D012189:Retrospective Studies
keywords: ICD-10; coding; emergency department; heart failure; validation