Conclusions
SECONDARY
In this study we used a novel, efficient prospective randomised controlled trial methodology to examine the rapid implementation and effectiveness of an active digital behavioural intervention across every GP practice in England. The RCT demonstrated that rapid large-scale implementation of a digital behavioural intervention is possible. While the trial did not demonstrate a difference in primary or secondary outcomes between the arms, we showed that it is possible to link intervention usage with individual practice health outcomes and to determine the effects of behavioural intervention engagement with health outcomes. Further work should explore how to improve rapid implementation and how this design can be applied to other types of intervention.