Hepatitis C tested prevalence and comorbidities among veterans in the US Northwest

GOALS: (1) Investigate the epidemiology of hepatitis C virus infection among patients seen in the Veterans Administration Northwest Network; (2) examine time trends in testing practices and results; and (3) estimate the prevalence of hepatitis C virus infection among active patients. BACKGROUND: Hepatitis C virus infection causes chronic hepatitis and cirrhosis and is a leading cause of end-stage liver disease. Hepatitis C virus antibodies are estimated to be present in 1.8% of the US population, but reports of its prevalence among US veterans range from 1.7 to 35%. STUDY: Retrospective review of computerized medical records of veterans tested for hepatitis C from October 1994 through December 2000 (n = 37,938) at 8 Northwest Veterans Administration Medical Centers. RESULTS: Among tested veterans, 8230 (21.7%) had evidence of hepatitis C virus infection. The number of patients tested increased annually from 2335 to 18,191, while the proportion with first-time positive hepatitis C test results decreased from 35 to 10%. This drop in tested prevalence was associated with a shift away from testing individuals at highest risk--those with positive hepatitis B serostatus, repeatedly elevated alanine transaminase levels, and drug use disorder diagnoses. We estimate that 11.4% of the Northwest Network veteran users are hepatitis C virus seropositive, with a lower bound of 4.0% and upper bound of 19.5%. CONCLUSIONS: Although estimates of hepatitis C virus infection rates among veteran users of the Veterans Administration system remain higher than those for the general population, changes in testing practice make generalizations from earlier studies hazardous.