Point-of-Care VL Testing
For participants randomized to the point-of-care VL intervention arm, all VLs during follow-up were conducted using the Xpert HIV-1 VL assay (Cepheid, Sunnyvale, CA). Initially, we planned for nurses to do the Xpert HIV-1 VL testing in the study clinic, but staff shortages and COVID-19–related disruption meant that it was conducted by a research laboratory technician in a clinical site laboratory in accordance with manufacturer instructions. In brief, a venous blood sample was centrifuged to provide 1 mL of plasma, which was tested using the Xpert HIV-1 VL cartridge. Participants were encouraged to wait for the result, which was provided to routine clinical staff to inform clinical management. If participants were not willing/able to wait, the results were provided at their next clinical appointment, scheduled by study staff in consultation with participants at the soonest possible date. In the case of invalid results, leftover plasma was used for retesting or a repeat sample was taken.