Mortality trends in Granulomatosis with Polyangiitis (GPA) 2004-2019 – a population-based study

Objective: To investigate nationwide mortality in incident Granulomatosis with polyangiitis (GPA) between 1 January 2004 until 31 December 2019 in Sweden.Method: Using the population-based National Patient Register, we identified patients with incident GPA, 2004-2019. Each patient with GPA was matched on sex and birth year to ten general population comparators. Follow-up began at disease incidence and continued until death, emigration or 31 December 2021. Mortality was assessed overall and stratified by sex and calendar time. Mortality rates (MRs) were calculated for patients with GPA and general populations comparators, and hazard ratios (HR) were calculated using weighted Cox proportional hazards regression.Results: Among 2322 patients with GPA and 22551 general population comparators, the crude MRs were 41.1 vs 26.5/1000 person-years (py), respectively. MRs were stable over calendar time. All-cause mortality was elevated in patients with GPA (HR: 1.5, 95% CI: 1.3-1.7), with similar results stratified by sex. The excess in mortality was ten times higher in the oldest age quartile (age at diagnosis) compared to the youngest (50 vs. 4 per 1000 py). Cumulative survival in GPA patients at 1, 5, 10, and 15 years was 93%, 82%, 68%, and 53%, respectively.,High risk of frailty was associated with more than doubled mortality (HR 2.4; 95% CI 1.8-3.1) compared to non-frail GPA patients, adjusted for age and sex in those aged ≥60.Conclusion: Patients with GPA had increased mortality compared to general population comparators, with the highest excess in mortality in older patients. Mortality remained stable over the study period.