Digital intervention for smell training: a real-world study on engagement, adherence, and behavioural dynamics

Despite advances in digital health, many interventions fail, not due to technical shortcomings, but because they are not meaningfully adopted or sustained in everyday life. Understanding real-world engagement remains a critical gap, especially in under-explored domains such as olfactory health. This study aimed to evaluate the real-world feasibility of a home-based Digital Smell Training (DST) system, focusing on how - participants - engage with it and sustain its use over time.

A six-month real-world feasibility study of a DST system, combining a scent-delivery device and mobile app, was tested in 18 UK households with and without olfactory disorders. A mixed methods approach captured adherence and user experiences over time.

Participants completed 74% of 5,600 potential sessions, showing high adherence to twice-daily training. Qualitative data revealed dynamic behavioural patterns: users’ motivations fluctuated over time, shaped by perceived progress, novelty effects, and evolving relationships with the intervention.

This study offers rare insight into how people engage with unfamiliar digital health tools outside controlled settings. Beyond the specific use case of smell, our findings highlight design and engagement strategies essential for achieving real-world impact, showing that sustained adoption hinges not just on innovation, but on behavioural understanding.