Hepatitis C virus (HCV) infection and liver-related mortality: a population-based cohort study in southern Italy

Background Hepatitis C virus (HCV) is a common cause of chronic liver disea ses but the degree to which these diseases contribute to liver-related mort ality is not well established. The aim of this study was to estimate the ab solute and relative effects of HCV infection on liver-related mortality. Methods A population random sample of 2472 Subjects aged greater than or eq ual to 30 years was enrolled and followed up from 1985 to 1996. At enrolmen t, a structured interview and a clinical evaluation were performed. Serum s amples were tested using HCV ELISA and RIBA HCV. Outcomes were overall and liver-related mortality and tracing procedures included review of office an d hospital records, death certificates, and interviews with general practit ioners, attending hospital and next of kin. Statistical analysis was perfor med using Poisson and binomial prospective data regression. Results Crude overall and liver-related mortality rates were 7.66 (95% CI:6 .68-8.79) and 0.9 (95% CI: 0.3-2.2) per 10(3) person-years, respectively. F or HCV infection effect, incidence rate ratio and difference (per 103 perso n-year), risk ratio and difference were 27.5 (95% CI : 6.5-115.6), 4 (95% C I: 3-7), 33.1 (95% CI: 7.8-139.3) and 0.06 (95% CI : 0.04-0.08), respective ly; all measures were adjusted for age at death, sex and daily alcohol inta ke. Conclusions The results show a strong relative but weak absolute effect of HCV infection on liver-related mortality in the 10-year period considered. Poisson and binomial models are virtually equivalent, but the choice of the summarizing measure of effect may have a different impact on health policy .