Non-probability sampling: The study population consists of adult patients over the age of 18 affected by CHC who were previously treated for the first time with Peg-IFN alfa-2b plus ribavirin and achieved end-of-treatment response. Five hundred ninety patients must be recruited in order to evaluate the objectives of the study. The patients must meet all inclusion criteria and not meet any of the exclusion criteria in order to be included in the study.