The Influence of Inhaled CorticoSteroids Adherence on Treatment Response to Mepolizumab in Severe Eosinophilic Asthma

Examine the outcomes of 250 patients who have been treated with mepolizumab within BRSAS and compare the adherence to ICS in the responders and non-responder groups. If confirmed that non-adherence to ICS was related to poor response to mepolizumab, steps then will be undertaken to better monitor and enhance adherence to ICS to improve patients outcomes and response to mepolizumab treatment. This study will rely on retrospective analysis of medically existing data within the service ,the adherence to ICS treatment will be measured using the prescription possession ratio "PPR" Data is available in the patients' GP records and forms part of the routine clinical practice of the severe asthma clinic to monitor adherence to ICS treatment. For a significant number of patients ,such data will be already available within patient medical records held at University Hospitals Birmingham NHS Foundation Trust (UHB), however missing data is expected and in such cases GP surgeries will be contacted to obtain the PPR. Patients will be asked to agree to access to GP records as part of the informed consent process.