Observational, Retrospective, Multicenter Study to Describe the Reasons for the Change of the Regimen of Antiretroviral Therapy in HIV Patients

Inclusion Criteria: * Patients older than 18 years * Patients with HIV * Patients in antiretroviral regimen, that have changed the antirretroviral treatment. Exclusion Criteria: * Patients unable to sign the consent form * patients that changing their treatment are going to take the same components in co-formulated * patients that changing their treatment are going to take the same components separately * Total or selective interrupts not indicated by the specialist * Patients that after changing antiretroviral therapy between January 2011 and July 2012, and during the next year, again suffered another change of treatment