This study took take place in 30 secondary schools, with year 8 and year 10 pupils.
Researchers compared pupil mental wellbeing in schools that restrict phone use, with schools that permit phone use (e.g. allow phones to be used at breaks and lunchtimes).
Researchers measured behaviours associated with mental wellbeing, such as, physical activity, sleep, attainment and classroom behaviour.
To collect this data, pupils completed a 30 minute online survey and wore an activity monitor watch for 7 days.
The class teacher and a member of the senior leadership team completed a 30 minute online survey.
In some schools, 60 minute focus groups with pupils, school staff and parents/carers took place.