ABSTRACT
Background: Anti-neutrophil cytoplasmic antibody-associated vasculitis (AAV) is a debilitating disease that can impact on a patient's quality of life. The aim of this study was to assess longitudinal quality of life among patients with AAV using the EQ-5D instrument. Method(s): 343 patients with AAV were recruited from the Irish Rare Kidney Disease Registry. The EQ-5D instrument was used to evaluate the domains of mobility, selfcare, usual activities, pain/discomfort, anxiety/depression and to generate an index score. Health was also rated using a visual analogue scale (0-100). Questionnaires were completed during nephrology clinics and through a patient support phone app. Data was screened for missing data and questionnaires with clear inconsistencies in responses were excluded. 2082 episodes and 283 patients were analysed. A random effects model was used to control for multiple entries relating to individual patients. Result(s): A poorer quality of life was seen amongst those with AAV (median index value 0.80, UK average 0.856). The mean visual analogue scale was 75.6 (UK average 82.8). Pain and discomfort levels were most affected while self-care was least affected. The index score decreased with increasing age with a 1.5% reduction in index score per decade. A 6% reduction in index score was seen during periods of disease activity compared to periods of remission. Patients requiring dialysis had a 5% reduction in index score. Covid-19 lockdown resulted in a 5.5% index score reduction. Using a median survival rate of 6.16 years for patients with small vessel vasculitis, we calculated the QALYs for this population as 4.9 years. Conclusion(s): We have defined for the first time the EQ-5D index value over the full disease course in patients with AAV. Other studies have demonstrated a reduction in quality of life during active disease using the AAV-PRO and the Medical Outcomes Study Short Form-36. A prior study among Japanese patients reported a mean index value of 0.72. This is lower than our observed index value however a smaller population (n=34) was examined. In conclusion, our research highlights the negative impact of AAV on patients' lives with a further reduction in quality of life seen during periods of increased disease activity, with increasing age and during the Covid-19 pandemic.