Analyses of Final Trends and Comorbidity of Eosinophilic Granulomatosis with Polyangiitis in Patients Hospitalized in Poland in 2014–2023

<b>Background</b>: Eosinophilic granulomatosis with polyangiitis (EGPA) is a rare vasculitis, and contemporary population data from Central and Eastern Europe are limited. <b>Aim</b>: To describe hospital-based incidence, patient characteristics and comorbidities among EGPA hospitalizations in Poland (2014-2023), including differences by age, sex and place of residence. <b>Methods</b>: This retrospective, population-based study used nationwide hospital discharge records with an EGPA diagnosis. First EGPA-coded hospitalizations were used to estimate annual incidence per 1,000,000 inhabitants. Demographics, duration of stay and accompanying comorbidities (cardiovascular disease, pulmonary disease, and asthma) were analyzed for all EGPA hospitalizations. Place of residence was classified as urban or rural. Group differences and temporal trends were assessed using appropriate parametric and non-parametric tests and regression models, with a two-sided <i>p</i> value < 0.05 considered statistically significant. <b>Results</b>: Between 2014 and 2023, 911 patients had a first EGPA-coded hospitalisation in Poland, corresponding to a mean annual hospital-based incidence of 2.38 per 1,000,000 inhabitants (range 1.28-3.38); incidence declined significantly from 2014 to 2019 (<i>p</i> < 0.001) and was disrupted during the COVID-19 period. Overall, 3524 EGPA hospitalisations were recorded, and women were more frequently hospitalised than men (54.5% vs. 45.2%; <i>p</i> < 0.001). Mean age at hospitalisation increased over time, with patients in 2023 being about 5-6 years older than in 2014 (<i>p</i> ≤ 0.009). Median length of stay was 8 days for first admissions and 5 days for all EGPA stays and shortened significantly over the study period (<i>p</i> < 0.001). Cardiovascular disease, pulmonary disease and asthma were present in 23.6%, 35.3% and 32.3% of patients, respectively. Cardiovascular disease was more common in men and in rural residents (both <i>p</i> < 0.001) and was associated with older age (<i>p</i> < 0.001), whereas pulmonary disease was associated with younger age (<i>p</i> < 0.001). Among women, the proportions with pulmonary disease and asthma decreased over time (<i>p</i> = 0.009 and <i>p</i> = 0.025). <b>Conclusions</b>: EGPA in Poland is rare, with hospital-based incidence comparable to other European and Asian populations. The hospitalized EGPA population is aging and cardiovascular comorbidity is increasingly prominent, especially in older and rural patients, while recorded pulmonary disease and asthma in women are decreasing.