Data collection methods for measuring engagement.

Digital health behaviour change interventions can face the challenge of low participant engagement, which can limit intervention effectiveness. Mixed methods approaches to understanding engagement, which capture the online and offline behaviours of participants, as well as the cognitive and affective aspects of engagement, are infrequently reported. The aim of this study was to explore these aspects of engagement for a digital intervention (Wrapped) to enable its optimisation ahead of testing in a randomised controlled trial (RCT). Wrapped is a digital intervention that aims to increase correct and consistent condom use, thereby decreasing the incidence of sexually transmitted infections among young people aged 16–24 years. Analytics data and website user history data were combined with data from surveys and qualitative interviews. Together this data was examined to assess the behavioural, cognitive, and affective aspects of engagement with the intervention. Results showed that participants experienced few barriers during the registration process, but that the tailoring questions used to assign content to individual users may not have been working as intended. Pre-determined intervention goals were as follows: ordering Sample Pack 48 (60.8%), using Condom Ordering Service 37 (52.9%), ordering Condom Carrier 31 (49.2%), watching Condom Demo video 7 (10%), watching Discussing Condoms video 4 (6.8%), and watching Real Life video 9 (13.6%). Participants described their use and enjoyment of the products they ordered; notably the condom carrier was less well liked and used. Participants reported not engaging with the video components, either because they were unaware that they existed or because they expected to find watching them to feel awkward. This study demonstrates that taking a mixed-methods approach to studying engagement provides a more complete understanding of where and how digital interventions need to be optimised than using single methods in isolation; this in turn is likely to lead to more effective interventions. Trial registration: ISRCTN Registry ISRCTN17478654.