On April 16, CDHI team members Prof. Dr. Marcia Nißen and Alexandre de Montleau traveled to Barcelona for a workshop on Engagement in Digital Health Interventions, as part of the ACM CHI 2026 Conference on Human Factors in Computing Systems.
Engagement sits at the center of nearly everything we build at CDHI, and yet, as a research subject, it remains underexplored. Alongside other researchers, we began sketching a shared research agenda for the field.
The format itself reflected the topic. Rather than sit through slide decks, participants — armed with post-its, and marker pens, worked through paired conversations, captured ideas on walls, and voted with our feet, literally walking to the “agree” or “disagree” side of the room as provocative statements were read aloud. The point was not just to discuss engagement, but to feel it.
A few ideas stood out:
Engagement is not a click.
High open rates can look impressive on a dashboard while revealing very little about whether someone is actually changing their behavior. The field needs metrics that capture whether a digital health intervention is helping a patient implement and sustain healthy habits — not simply whether the app is being opened.
High open rates can look impressive on a dashboard while revealing very little about whether someone is actually changing their behavior. The field needs metrics that capture whether a digital health intervention is helping a patient implement and sustain healthy habits — not simply whether the app is being opened.
Co-design beats hand-off.
Interventions designed with end users in the loop — whether during early development or through later customization — tend to be more relevant, more usable, and ultimately more engaging. Engagement begins long before launch.
Interventions designed with end users in the loop — whether during early development or through later customization — tend to be more relevant, more usable, and ultimately more engaging. Engagement begins long before launch.
Wellness, in excess, can produce its opposite.
Talking about wellness every day can create the very anxiety it claims to relieve. A poor sleep score delivered at 7 a.m., after a night that felt perfectly fine, can color an entire day. Interventions need to know when to step back.
Talking about wellness every day can create the very anxiety it claims to relieve. A poor sleep score delivered at 7 a.m., after a night that felt perfectly fine, can color an entire day. Interventions need to know when to step back.
Reflection is not a feature; it is a layer.
Several participants argued that digital health interventions need an explicit reflection layer — moments designed for users to notice, interpret, and integrate what the intervention is telling them. Without it, data accumulates without becoming meaning.
Several participants argued that digital health interventions need an explicit reflection layer — moments designed for users to notice, interpret, and integrate what the intervention is telling them. Without it, data accumulates without becoming meaning.
Good nudges work themselves out of a job.
The aim is to help patients build healthy behaviors that eventually outlive the app — not create lifelong dependence. Closely linked to this is the need for a reflection layer: engagement runs deeper when users can step back and make sense of their own progress, rather than simply reacting to the next notification.
The aim is to help patients build healthy behaviors that eventually outlive the app — not create lifelong dependence. Closely linked to this is the need for a reflection layer: engagement runs deeper when users can step back and make sense of their own progress, rather than simply reacting to the next notification.
Agency is a balance to be designed, not assumed.
How much should the intervention decide for the user, and how much should the user decide for themselves? There is no universal answer, but the question itself deserves a central place in the design conversation.
How much should the intervention decide for the user, and how much should the user decide for themselves? There is no universal answer, but the question itself deserves a central place in the design conversation.
We left Barcelona with new collaborators, a sharper sense of what the field is missing, and a list of ideas we intend to bring into our own workflows at CDHI. The most useful reminder, perhaps, was the simplest: engagement is not the goal of a digital health intervention. Better health is. Everything we measure should serve that distinction.