 The main objective of this project is to start from patients experiences to develop a disease specific PRO for patients with AAV. Patients diagnosed with AAV will be recruited through clinics or inpatients at the Oxford University Hospitals OUH National Health Service NHS Trust, or, if the patients have previously consented to be contacted about future studies, through the Diagnostic and Classification of Vasculitis DCVAS or The Characterisation and Determinants of Quality of Life in ANCA Associated Vasculitis VasQoL study databases. After informed consent is obtained, individual patient interviews will be conducted; these will last for approximately one hour and will be recorded and transcribed. Themes will be independently extracted and amalgamated by the researchers. Approximately 25 patients with different types of ANCAassociated vasculitis and varying disease duration will be interviewed until saturation, i.e., no new substantive themes emerge. These themes will then evolve into individual candidate questionnaire items. Candidate items will be piloted on approximately 25 different patients with AAV using questionnaires and interviews, until no further comments arise, to produce a final set of candidate questionnaire items. The duration of the study 1.5 years. 