The trial will aim to assess the acceptability, uptake and success in collecting follow up data and variance in asthma-related outcome measures. A parallel group design will be used with participants being randomised to intervention or normal management. The intervention will be a self-guided, breathing retraining digital intervention, delivered via a mobile-friendly, online platform. The intervention will continue to be used for 6 months after which both groups will be reassessed. The usual management control group will then have access to the intervention (delayed access).
