Antecedents and consequences of different indicators of engagement with a digital intervention for tobacco cessation

Mobile apps are commonly used to deliver digital interventions, typically through prompts that encourage engagement with intervention contents. However, engagement with these interventions remains suboptimal. A recent organizing framework conceptualizes digital interventions as a sequence of stimuli/tasks, underscoring the importance of measuring engagement with each stimulus/task separately. We applied this framework to a tobacco cessation intervention study that used an app to deliver prompts for practicing self-regulatory strategies. We found that engagement with certain stimuli/tasks (e.g., messages describing a low-effort strategy) declined over time, whereas engagement with others (e.g., messages recommending a more effortful strategy) remained stable. Initiating a brief in-app survey prior to prompting increased the likelihood of engaging with the intervention prompt, but not with subsequent messages or recommended strategies. These findings support conceptualizing engagement as a dynamic, multistage process and offer practical insights for optimizing engagement with digital interventions.