Randomization
A total of 1160 opaque security envelopes (580 intervention and 580 control) were used to randomize participants in a 1:1 ratio by following a randomized block design in groups of 10. Blocks were distributed equally between the urban and rural sites. This block design reduced variability within treatment conditions and potential confounding, allowing for interim analysis with near equal–size groups and more certain randomization within sites. The site coordinators were unaware of the envelope’s contents until the participant opened and revealed the group assignment to the coordinator. Randomization affected participant intervention only after routine VMMC surgical procedure and recovery. The study design required that the participants and clinic staff be aware of the allocation after the assignment.