“…4 Nonadherence to treatment in chronic processes in general is a well-known problem, and the reasons would seem to be multiple, including factors relating to health (quality of the health/patient relation), and individual, sociodemographic, psychosocial, and clinical factors (type of disease, unwanted side effects, or complexity of the therapy). 5,6 In 2003 Spain had a prison population of 54,497 inmates. 7 This large population is affected by various health problems, the most frequent being those of parenteral transmission [hepatitis C virus (HCV) and mainly HIV], as well as tuberculosis, psychiatric illnesses, and drug abuse.…”