Randomization and blinding procedures
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The randomization schedule, developed by a biostatistician, assigned participants categorized as ‘responders’ to either naltrexone/bupropion or placebo (double-blind) for 16-weeks using stratified blocked randomization with the initial acute treatment as a stratifying variable. The schedule comprised random block sizes of two and four to obviate secular trends and to yield approximately equal proportions. Participants and clinicians remained blinded as to whether they had received naltrexone/bupropion in their initial acute treatment stage, in addition to once again being blinded to their randomized medication condition in this trial. Assessors of outcomes were blinded to whether participants had received BWL during their prior Stage 1 treatment in addition to the (double-blind) medication in both the prior and current trials.