Every patient who is registered in the ART service has a Mastercard. At each visit, for a clinical consultation, a psychosocial support session or a drug pick-up, the Mastercard is updated by a health professional. For each clinical consultation the ‘Ficha Clínica’ of the Mastercard must be updated in a standardized way, where every two lines represent a clinical consultation taken place on a given date and where the headings of the columns as the guiding instructions indicate which information has to be registered in each field.