Implementation process
To explore whether a heterogeneous sample of local primary schools was able to use the ACTIPROS toolbox, we tracked the implementation of interventions over the course of one school year at each intervention site. Members of the research team were in contact with each intervention site over the course of the implementation period and documented the implementation process. Through personal and telephone contact schools reported their intervention choices, implementation issues and changes to the initial planning while working with the toolbox. Complementary, at t1, teachers of intervention classes were asked to fill out a short implementation questionnaire (SIQ) where they had to document intervention choices, for how long each intervention was implemented and how often intervention sessions took place. Teachers were asked to return the SIQ either electronically or via mail and up to three reminders were send to teachers by the research staff between July and September 2022.