Randomization
RECRUITMENT, RECRUITMENT
Recruitment and randomization were organized in clusters of workplace-units, with employees and their immediate supervisor. In addition, supervisors who were linked to the same workplace were randomized together. Workplace-units were randomized in blocks of 6, in a 1:1 ratio to either the experimental or to the control (comparator) condition. Randomization was conducted by an independent researcher associated with the team. A pre-generated allocation sequence was concealed in envelopes which were opened upon enrolment of supervisors at a given workplace. To minimize participant expectations during recruitment, the same information about the study was provided to both groups and information about the interventions was sparse and manualized.