Limitations
Despite the strengths of CC approach as we have used it in trial design, some challenges remained. For example, in Nigeria, large gatherings of people can be mistaken for/perceived as a call for political aims. In implementing this methodology, the purpose should be well communicated not only to study participants, but also to the broader community as well. While participants were fully aware of the purpose of the conversations, other members of the community who had not heard about the meeting, initially felt that it was a political gathering and questioned why they were excluded, and they tried to politicise it. In this instance, we were able to reschedule our meetings for another day, ensuring a wider range of invitations. This suggests that for others applying this approach in highly politicised contexts, CCs should be opened even wider, more in line with their original approach with open public forums.Our sampling approach was designed to include anyone eligible for the final intervention, ensuring that participants would also be likely to include in the trial at some later stage. By organising activities within this approach by sub-group, we attempted to reduce the potential for exclusion faced by some community members (such as young women). However, this did not allow us to include all vulnerable groups — as some sub-communities (such as the poorest members of the Hausa tribe) may have struggled to participate over the multiple days of data collection. Unfortunately, we did not record details on non-attendees on the second day of CC sessions, which is another limitation. Future studies may want to explore how actors ‘voting with their feet’ promote additional learnings about the potential interventions.The need for repeat attendance at CCs can influence the effectiveness of the approach. To counter this, we held our conversations over the course of 2 days to reduce demands on time. in contrast with the original application, which can be run over weeks and months. In applying CCs within trial settings we suggest an acknowledgement of how time away from employment, school or training can impact well-being as well as the ability to engage in these processes. Appropriate compensation schedules that align with the time investment of communities are critical and are an equitable way to acknowledge the importance of everyday knowledge to scientific processes especially when this method extends for longer periods.Finally, the approach is also resource intensive. Our ability to conduct this approach effectively was facilitated through the involvement of four community researchers devoted to the qualitative aspects of the formative research. It is imperative that these aspects of research are appropriately costed, to enable in-depth exploration.