Screening for hepatitis C virus infection in adults: a systematic review for the u.s. Preventive services task force.

Identification of hepatitis C virus (HCV)-infected persons through screening could lead to interventions that improve clinical outcomes. To review evidence about potential benefits and harms of HCV screening in asymptomatic adults without known liver enzyme abnormalities. English-language publications identified from MEDLINE (1947 to May 2012), the Cochrane Library Database, clinical trial registries, and reference lists. Randomized trials and cohort, case-control, and cross-sectional studies that assessed yield or clinical outcomes of screening; studies reporting harms from HCV screening; and large series reporting harms of diagnostic liver biopsies. Multiple investigators abstracted and checked study details and quality by using predefined criteria. No study evaluated clinical outcomes associated with screening compared with no screening or of different risk- or prevalence-based strategies. Three cross-sectional studies in higher prevalence populations found that screening strategies that targeted multiple risk factors were associated with sensitivities greater than 90% and numbers needed to screen to identify 1 case of HCV infection of less than 20. Data on direct harms of screening were sparse. A large study of percutaneous liver biopsies (n = 2740) in HCV-infected patients with compensated cirrhosis reported no deaths and a 1.1% rate of serious adverse events (primarily bleeding and severe pain). Modeling studies were not examined. High or unreported proportions of potentially eligible patients in the observational studies were not included in calculations of screening yield because of unknown HCV status. Although screening tests can accurately identify adults with chronic HCV infection, targeted screening strategies based on the presence of risk factors misses some patients with HCV infection. Well-designed prospective studies are needed to better understand the effects of different HCV screening strategies on diagnostic yield and clinical outcomes. Agency for Healthcare Research and Quality.