In the Phase IIIB MTN-025/HOPE open label extension trial, participants were offered the dapivirine vaginal ring as HIV prophylaxis, and those who accepted the ring received semi real-time individual adherence feedback, based on residual drug level (RDL) from returned rings, during Motivational Interviewing-based counseling. Counseling messages, based on the best knowledge at the time, framed RDL results in terms of ring use and HIV protection, from no use /no protection (0 RDL) to high use /high protection (3 RDL). At six HOPE sites, in-depth-Interviews (IDIs) about RDL were conducted with 64 participants who had received at least one RDL result. We found mixed interpretations of what the RDL meant and strong emotional reactions with a focus on the external validation of the level itself. Counseling was critical to help participants process their reactions to the RDL and make decisions accordingly (i.e., persistence, adherence improvement, and/or switching to another HIV prevention method). Providing drug adherence feedback was complex to implement yet proved useful as a component of a multi-pronged adherence support strategy.
