CD4 and HIV infectious disease: In the CoRIS cohort in Spain, also part of the ART-CC, where interruptions were defined using gaps of >15 months, risk factors for interruption included younger age, lower educational level, having acquired HIV infection through injecting drug use or heterosexual intercourse, having been born outside of Spain, and CD4+ cell count >200 cell/μl, viral load <100 000 and co-infection with hepatitis C virus at enrolment [21].