Table 1 Examples of interview questions aimed at confirming or falsifying intervention assumptions

Looking for mechanisms or unintended responses:

▪ “Your CONNECT website was linked in with your health record at the general practice. We expected that this could be an important innovation that would interest people, and that it might prompt greater interest in their own health situation. Was that the case for you?” [questioned further if answer was yes/no]

▪ “When we built the heart risk screen, we assumed that people would react to it by thinking about their personal heart health risk and possible steps they could take to improve it, maybe to discuss it a little more with their GP. Did that heart risk screen have an impact for you?”

▪ “As with many other technology-based programs for improving health, we included screens where you could set and track personalised goals because we suspected that this is a feature people like to use to see their achievements and keep motivated. It could be different for others. What do you think about it?

Looking for mechanisms; exploring contexts of use:

▪ “In what ways do you think technology can be helpful for people who are trying to increase healthy lifestyle behaviour? What features do you feel are important?”

▪ “People are motivated to improve their heart health for many different reasons. For you, what were reasons to start or increase healthier behaviour?”

▪ “Can you tell me about things in the CONNECT program that you read or used that helped you think about risk for heart disease, or made you want to make some lifestyle changes?”