Primary acceptability endpoint
Acceptability endpoints were based on participants’ responses to the CASI for each product at their respective product use end visits (Visits 3, 5 and 7). Using a 10-point scale (1 = Very Unlikely; 10 = Very Likely), participants were asked to answer the following question about their most recently used product: “Think about the positive and negative experiences you have had using the [study product] during the past 4-week period. If this [study product] was available and it provided some protection against HIV, how likely would you be to use it before receptive anal sex?”. The endpoint was operationalized as binary, with scores 1 to 6 grouped as “low acceptability” and scores 7 to 10 as “high acceptability”.