Discussion
movement behaviors
LITTLE
This is the first study to examine the components (target behaviors, delivery features and BCTs) of INFANT, an early life nutrition and movement behavioral intervention from RCT to scale-up. We found few published research studies that presented BCTs of scaled-up behavior change interventions in other disciplines. For example, one study described using BCTs to inform implementation strategies (Our results highlight that the scaled-up version of the INFANT intervention stayed true to the initial purpose to promote healthy nutrition and movement behaviors in early childhood. The target population and target behaviors were expanded, and the delivery features were adapted for scale-up. The BCT mapping showed that the intervention was largely using the same techniques to change behaviors. The main changes seen in BCTs identified for the RCT vs. scale-up corresponded to modifications made for scalability and in response to temporal changes, such as the enhanced technology available, with these two iterations occurring more than a decade apart. With the exception of new content around milk feeding (breastfeeding, formula feeding and mixed feeding), we utilized app capabilities (push notifications, quizzes providing personal feedback, parent forum) to reinforce messages received in the intervention and the app enabled increased opportunity for BCT inclusions. Unpacking the intervention components lays the foundation for understanding the implementation-effectiveness outcomes as the scale-up of INFANT progresses, as well as exploring the reasons for the potential scale-up “penalty” when moving from RCT to scale-up.In comparing the intervention components of the INFANT RCT and scaled-up versions, it is important to highlight that the scale-up is currently in progress and therefore the reported data is for the planned, rather than actual, intervention implemented. Scaled-up interventions are much more likely to be modified and adapted than an RCT given that scale-up implementation is led by local delivery organizations and applied to local contexts (Little is known about the associations between intervention components, including BCTs, and outcomes, and assessing this is challenging (There is limited evidence regarding an ideal number of unique BCTs to support behavior change and scarce evidence about the optimal frequency or “dose” of BCTs. It is plausible that a greater number of unique BCTs and repetition throughout an intervention could see greater behavioral outcomes. A systematic review of internet-based behavior change interventions found that the greater number of BCTs used correlated to larger intervention effects (