Randomisation and masking
The samples across the two regions were pooled to estimate intervention effects. We used stratified randomisation by woreda, to balance potential co-interventions and confounders, and by school size. Then, schools were randomly allocated to the intervention or the control group by use of computer-generated pseudo-random numbers before the baseline survey.The evaluation study was non-masked for all participants, programme implementers, and the research team, including analysts. Adolescents and parents in the intervention group were not informed about the results of the randomisation, but there was no masking of the interventions at schools or other points of contact. At the time of enrolling and interviewing participants, assessors were not informed about intervention allocation, and the intervention allocation variable was added into the datasets at the time of data analysis after data cleaning.