Randomization, allocation concealment, and blinding
BLIND
Randomization was stratified by gender (female Participants were not blind as to whether they were receiving an intervention or monitoring only, but otherwise were blind to the nature of the different versions of the intervention being tested. The research team were not blind to participant allocation, although only had minimal contact with participants (e.g. responding to messages). One researcher (SEB) monitored performance of the arms as data accumulated, via the sequential analyses, and shared outcome data with other researchers (FDS, MLW, AW, JM) for the purpose of decision-making. These researchers were therefore not blind to outcomes as the trial progressed.