Lost To-Follow-Up (LTFU): defined as HIV-infected adults (18 years or older) who made a visit to one of the 30 public, CIDRZ-supported clinics and were late for their last scheduled visit for 90 days or more for those on ART, and late for more than 180 days for those not yet on ART [1].

Official Transfer: refers to patients on ART who were given an official transfer letter from their original health facility to attend another health facility providing ART services [2].

Silent Transfer: refers to patients considered LTFU from their original health facility who were found to be in HIV care at another health facility because they had decided to transfer without informing their original health facility [1].

Treatment supporter/buddy: someone who is chosen by an HIV patient to provide him or her with ongoing support for adherence to care and ART treatment.