This is a randomized clinical trial involving patients who between 2013 and 2017 have contacted the drug dependence center and patients from general population.~After selecting those who do not meet any exclusion criteria, a letter will be sent to them inviting them to participate in this study. This letter will contain the study information sheet and informed consent, and a self-testing kit with an explanatory leaflet so that each person can carry out the test in a simple and easy way.~The main purpose of the study is to evaluate the acceptance and viability of self-testing using dried blood spot (DBS) testing, to study whether support improves participation and to identify predictors of participation.~For the present study, assuming an increase of 18% participation (from 18% to 28% offering support by the patient's referral center, and based on a previous study in our environment of self-testing in the general population), taking into account a power of 80%, alpha error of 5%, and losses of 20%, will require 346 patients per group.
The main purpose of the study is to evaluate the acceptance and viability of self-testing using dried blood spot (DBS) testing assisted by center of origin or referral hospital, as a strategy for screening for hepatitis C virus (HCV) in high risk population (ex-users of drug dependence centers) compared to the general population assisted by primary care centers.