Procedures
sexual behaviors
We randomized participants to the following groups: (1) 6-month PrEP dispensing with HIVST, which included a 6-month drug supply, 2 HIVST kits, and semiannual clinic visits or (2) standard of care (SOC) PrEP dispensing, which included a 3-month drug supply, no HIV self-tests, and quarterly clinic visits. Participants in the intervention group were further randomized to receive either 2 blood-based or 2 oral-fluid HIVST kits. All participants received a PrEP supply of tenofovir disoproxil fumarate/emtricitabine or lamivudine (TDF/FTC or 3TC). Participants in the SOC group were scheduled for quarterly clinic visits (at 3, 6, 9, and 12 months), and those in the intervention group were scheduled for semiannual clinic visits (at 6 and 12 months).Participants in the intervention group randomized to blood-based HIVST received Mylan Rapid HIV 1&2 tests (Mylan Lab Ltd), and those randomized to oral-fluid HIVST received OraQuick Rapid HIV-1/2 Antibody Tests (OraSure Technologies). At enrollment, all participants in the intervention group received training by study staff on the HIVST process, HIVST informational brochures (in English and Kiswahili), and a toll-free helpline phone number for 24-hour, on-demand support (if needed); they were encouraged to use 1 HIV self-test midway between PrEP clinic visits (ie, 3 months following refilling) and the other as desired (ie, for back-up testing, partner testing, or testing between clinic visits).At every scheduled clinic visit, we delivered PrEP services following the 2018 Kenya National PrEP GuidelinesTrained research assistants completed electronic questionnaires (CommCare [Dimagi]) with participants at each clinic visit. The questionnaires included information on participants’ demographic characteristics, use of HIV testing (including HIVST), health-seeking and sexual behaviors, and HIV testing preferences. At the 6- and 12-month clinic visits, we also collected dried blood spot (DBS) samples from each participant for biologic adherence measurements.