The validity of International Classification of Diseases-9 codes for liver disease has not been determined.
Dr Kramer and colleagues from Texas, USA examined the accuracy of International Classification of Diseases-9 codes for cirrhosis with Hepatitis C virus, alcoholic liver disease, HIV or Hepatitis B virus coinfection with Hepatitis C virus in Veterans Affairs data.
|Hep C virus codes, the positive predictive value was 93% |
|Alimentary Pharmacology & Therapeutics|
The research team conducted a retrospective study comparing the Veterans Affairs administrative data with abstracted data from the Michael E. DeBakey VA Medical Center's medical records.
The team calculated the positive predictive value, negative predictive value, per cent agreement and kappa value.
The positive predictive value is the probability that cirrhosis is present among those with a code.
The negative predictive value is the probability that cirrhosis is absent among those without a code.
The researchers found for cirrhosis codes, that the positive predictive values, and negative predictive values were 90% and 87% with 88% agreement and kappa of 0.70.
For Hepatitis C virus codes, the positive predictive value and negative predictive value were 93% and 92%, yielding 92% agreement and a kappa of 0.78.
For alcoholic liver disease codes, the positive predictive value and negative predictive value were 71% and 98%, with 89% agreement and kappa of 0.74.
The researchers found that all parameters for HIV coinfection with Hepatitis C virus were over 89%.
However, the codes for Hepatitis B virus coinfection had a positive predictive value of 43% to 67%.
Dr Kramer's team concluded, "These diagnostic codes, except for 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."