Data confidentiality Each participant will be assigned a unique identification number upon recruitment. Patients' contact details will be held on a separate database and used to arrange study visits. The database will be password protected and only members of the research team contacting patients will have access. All data collected during the study will be stored anonymously on a separate database. Again access will be password protected and restricted to relevant members of the research team. Electronic data will be stored in the University or NHS system.