MISSION is a new and novel way of delivering highly specialised asthma care and has the potential to change the way asthma care across the United Kingdom (UK) is delivered as well as services for other long term health conditions. The MISSION model is the first model of this type and the current research study aims to evaluate its success and to compare the MISSION service to current care delivery. This will be done in several different ways. The study is a mixed methods evaluation of the new service comparing outcomes before and after the intervention using retrospective data analysis and prospective qualitative interview. A control arm of patients not exposed to, but eligible for, the new intervention will also be included. The study will be conducted at Portsmouth Hospitals National Health Service (NHS) Trust and will recruit patients who attended MISSION clinics, outpatient asthma clinics, staff who attended MISSION clinics in a professional capacity and patients from GP surgeries where MISSION clinics were held who did not attend.