The Burden of Hepatitis C Infection-Related Liver Fibrosis in the United States.

BACKGROUND Knowledge of the estimated proportion of hepatitis C virus (HCV)-infected persons with advanced fibrosis or cirrhosis is critical to estimating healthcare needs. METHODS We analyzed HCV-related testing conducted by Quest Diagnostics from January 2010 through December 2013. Tests included hepatitis C antibody, HCV RNA, HCV genotype (nucleic acid tests [NAT]), liver function tests, and platelet counts; patient age was also determined. Aspartate aminotransferase (AST)-to-platelet ratio (APRI) was calculated as = 100*(aspartate aminotransferase [AST]/upper limit of AST)/platelet. Fibrosis-4 (FIB-4) was calculated as (age × AST)/(platelet ×√ alanine aminotransferase [ALT]). Persons were "currently infected" if they had ≥1 positive HCV NAT; "in care" if a positive RNA test was followed <6 months by ≥1 additional NAT(s), or ALT, AST, and platelets <90 days, or any test ordered by an infectious diseases or gastroenterology specialist; and "evaluated for treatment" if they had a genotype test. RESULTS Approximately 10 million HCV test results were analyzed, representing 5.6 million unique patients. Of the 2.6 million patients with data to estimate liver disease, 5% were currently infected. Among those currently infected, APRI and FIB-4 scores indicated that 23% overall-and 27% among the cohort born during 1945-1965-had advanced fibrosis or cirrhosis at first diagnosis. A total of 54% of infected were in care and 51% of infected with advanced fibrosis or cirrhosis were evaluated for treatment. CONCLUSIONS Testing from a large US commercial laboratory indicates that about 1 in 4 HCV-infected persons have levels of liver disease put them at highest risk for complications and could benefit from immediate antiviral therapy.