Abstract
BACKGROUND: Switzerland has taken a different path to cannabis regulation than other countries. A 2021 law allows regulatory experiments on the production and sale of cannabis for non-medical purposes. The research team planned a randomised controlled trial (RCT) to test how selling cannabis in pharmacies affects users' health and consumption habits. The study intervention also included counselling on risk reduction, such as smoking cessation. The research team aimed to incorporate the perspectives of people who use cannabis into the study design, despite challenges related to stigma and legal constraints. METHODS: When planning the RCT, the research team mandated an external researcher to form an advisory group with regular users of non-medical cannabis. This researcher used convenience sampling (including snowball sampling) to recruit people who use cannabis, considering age, self-reported gender and cannabis use frequency. She conducted an individual interview, followed by iterative group discussions. She summarised the results into reports and sent them to the research group, who considered the results during study planning and formulated topics to be discussed in the next advisory group meeting. RESULTS: In a two- and half-year long process (November 2021 to March 2024), eight people who use cannabis provided iterative feedback that informed the development of the study intervention. Based on their feedback, the research team expanded the product selection to include cannabis resin alongside cannabis flowers. The group's feedback also led the research team to make several changes to the sales process in pharmacies. While the members of the advisory group expressed that much of their feedback had been considered, they noted that some key aspects - such as product pricing - had not been implemented. Legal and political constraints limited the research team's ability to implement advisory group feedback. CONCLUSIONS: This experience showed that gathering user input is feasible, even in highly regulated, stigmatized contexts. Including the perspectives of people who use cannabis in the trial set-up allowed the research team to adapt the study intervention. Where they could not adapt the study intervention, it helped them prepare for possible reactions from future study participants and disseminate their findings to other stakeholders. Future research should test the feasibility and benefits of such activities throughout all research stages.