Mortality and cause of death in patients with ANCA-associated vasculitis and polyarteritis nodosa in Australia—a population-based study: a population-based study

Objectives We compared survival and causes of death in Western Australian (WA) ANCA-associated vasculitis (AAV) and PAN patients with controls and the WA population. Methods In this data linkage study, we identified patients with incident AAV/PAN and age, sex and temporally matched controls 1980-2014 from the WA Rheumatic Disease Epidemiological Registry. Survival analyses and time-varying analyses were performed. Results Six hundred and fourteen patients with incident AAV/PAN were compared with 6672 controls; 229 AAV/PAN patients died over 5277 person-years of follow-up and 1009 controls died over 73835 person-years. Survival was reduced in patients with AAV/PAN compared with matched controls [hazard ratio (HR) 3.5 (95% CI: 3.1, 4.1)], and matched WA population rates [standardized mortality ratio 3.3 (95% CI: 2.9, 3.8)]. Greatest excess mortality in AAV/PAN patients was observed in the first year after diagnosis and remained higher than controls throughout follow-up. Greater excess mortality was observed in patients >60 years at diagnosis. In cause-specific analyses, mortality HR for vasculitis, infection and non-infective respiratory disease were greatest early after diagnosis and remained persistently elevated. The HRs for malignancy and cerebrovascular disease related deaths increased during follow-up, and were constant for ischaemic heart disease related deaths. Conclusion Mortality was increased in AAV/PAN patients compared with controls, with patients older at diagnosis at greater risk. These findings provide mortality risk for AAV/PAN in an Australian population, highlighting key contributors to mortality at different time periods over follow-up and potential areas of focus for reducing mortality.