title: The validity of viral hepatitis and chronic liver disease diagnoses in Veterans Affairs administrative databases.
abstract: BACKGROUND
  The validity of International Classification of Diseases-9 codes for liver disease has not been determined.
  
  
  OBJECTIVE
  To examine the accuracy of International Classification of Diseases-9 codes for cirrhosis with hepatitis C virus or alcoholic liver disease and HIV or hepatitis B virus coinfection with hepatitis C virus in Veterans Affairs data.
  
  
  METHODS
  We conducted a retrospective study comparing the Veterans Affairs administrative data with abstracted data from the Michael E. DeBakey VA Medical Center's medical records. We calculated the positive predictive value, negative predictive value, per cent agreement and kappa.
  
  
  RESULTS
  For cirrhosis codes, the positive predictive value (probability that cirrhosis is present among those with a code) and negative predictive value (probability that cirrhosis is absent among those without a code) were 90% and 87% with 88% agreement and kappa = 0.70. For hepatitis C virus codes, the positive predictive value and negative predictive value were 93% and 92%, yielding 92% agreement and kappa = 0.78. For alcoholic liver disease codes, the positive predictive value and negative predictive value were 71% and 98%, with 89% agreement and kappa = 0.74. All parameters for HIV coinfection with hepatitis C virus were >89%; however, the codes for hepatitis B virus coinfection had a positive predictive value of 43-67%.
  
  
  CONCLUSIONS
  These diagnostic codes (except hepatitis B virus) in Veterans Affairs administrative data are highly predictive of the presence of these conditions in medical records and can be reliably used for research.
authors.affiliation: Houston Center for Quality of Care and Utilization Studies, Michael E. DeBakey Veterans Affairs Medical Center, Houston, TX, USA. jkramer@bcm.tmc.edu
authors.forename: J R
authors.initials: JR
authors.lastname: Kramer
authors.forename: J A
authors.initials: JA
authors.lastname: Davila
authors.forename: E D
authors.initials: ED
authors.lastname: Miller
authors.forename: P
authors.initials: P
authors.lastname: Richardson
authors.forename: T P
authors.initials: TP
authors.lastname: Giordano
authors.forename: H B
authors.initials: HB
authors.lastname: El-Serag
mesh_terms: D000328:Adult; D005260:Female; D015658:HIV Infections / Q000175:diagnosis / Q000821:virology; D006509:Hepatitis B / Q000175:diagnosis / Q000821:virology; D006526:Hepatitis C / Q000175:diagnosis; D006525:Hepatitis, Viral, Human / Q000175:diagnosis* / Q000821:virology; D006801:Humans; D038801:International Classification of Diseases; D008103:Liver Cirrhosis / Q000175:diagnosis; D008107:Liver Diseases / Q000175:diagnosis*; D008108:Liver Diseases, Alcoholic / Q000175:diagnosis; D008297:Male; D016347:Medical Records Systems, Computerized; D008875:Middle Aged; D011336:Probability; D012189:Retrospective Studies; D014481:United States; D014493:United States Department of Veterans Affairs / Q000706:statistics & numerical data