Experiences Participating in Rectal Microbicide Clinical Trials: Insights from MTN-026 & MTN-033



Successful implementation of clinical trials depends on participants’ engagement with and commitment to study protocols. Increasingly, implementation scientists have noted the importance of examining how internal (e.g., experiences with study procedures and staff) and external (motivations for participating) factors influence participants’ engagement with clinical trials. As part of two Phase I rectal microbicide clinical trials (MTN-026 and MTN-033), we ascertained how internal and external factors facilitated participants’ engagement throughout the clinical trial experience.


Forty-four participants (age range: 19-47; 35 male, 9 female) were enrolled across three sites (Bangkok, Thailand and Birmingham, Alabama and Pittsburgh, Pennsylvania, USA) and completed semi-structured, video-facilitated in-depth interviews (IDI). During these interviews, we explored participants’ study experiences, including motivations to participate in the trial and comfort with clinical (e.g., anoscopy) and behavioral (e.g., surveys and IDIs) procedures. Interviews were conducted by trained qualitative interviewers, transcribed, coded, and analyzed for key themes. Thematic analysis examined convergent and divergent themes emerging from the interviews.


Majority of participants noted numerous positive motivations for participating in the trial (e.g., contributing to the development of HIV prevention products, healthcare access), and voiced how their interactions with clinical staff supported their trial participation (e.g., flexible scheduling). Participants highlighted their appreciation for staff being receptive to feedback, clearly explaining study procedures, and asking for consent before performing a procedure. While some participants mentioned feeling discomfort during clinical procedures (e.g., biopsies), they discussed the importance of the study and offered behavioral strategies to overcome discomfort during study procedures (e.g., watching Netflix on their phone, listening to music, or looking away from the monitors). No thematic differences regarding study procedures were observed between Thai and US participants.


Ensuring participants’ optimal engagement with study protocols is a pivotal aspect of any trial. Our findings support the need for multiple strategies staff can advise participants to engage in to overcome discomfort during study visits. Additionally, beyond acceptability of an investigational drug, our findings underscore the need to support planning and implementation efforts seeking to enhance internal (e.g. scheduling of and interactions during clinic visits) and external (e.g. altruistic motivators) factors linked to participants’ trial experience and engagement.