| Abstract [eng] |
Objectives The aim of this study was to assess the incidence, prevalence and mortality of anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) in Lithuania. Design Retrospective cohort study. Setting Lithuanian National Health Insurance Fund and Causes of Death registries, covering 1 January 2012 through 31 December 2021. Participants Patients were identified from national healthcare registries in Lithuania. The following inclusion criteria were applied: 1) diagnosis of eosinophilic granulomatosis with polyangiitis (EGPA), granulomatosis with polyangiitis (GPA) or microscopic polyangiitis (MPA) (diagnosis codes M30.1, M31.3 and M31.7, according to International Classification of Diseases 10th version (ICD-10)) recorded between 1 January 2012 and 31 December 2021; 2) diagnosis of AAV was recorded in the database at least twice with at least 1-month period between the two timepoints; 3) a record of at least once prescribed reimbursed medication—glucocorticoids (prednisolone or methylprednisolone), conventional synthetic disease-modifying anti-rheumatic drugs (methotrexate, azathioprine, hydroxychloroquine and cyclophosphamide) or biological disease-modifying anti-rheumatic drug (rituximab or available biosimilars); and 4) age >18 years at the time of diagnosis. Outcome measures Data for the analysis included sex, age, ICD-10 code of AAV, the first date of AAV diagnosis and date of death. The study period was subdivided into periods 1 (2013–2015), 2 (2016–2018) and 3 (2019–2021). Temporal trends of the incidence of AAV were assessed. Point prevalence data were recorded. Sex- and age-standardised mortality ratios (SMRs) were calculated. The life expectancy of patients with AAV was estimated by standard single-decrement life-table analysis. Results We identified 236 patients with AAV (female, 58%) with an annual incidence of 8.22 per 1000000 adult inhabitants (period 1, 9.83; period 2, 6.88; period 3, 7.95). Increasing incidence was noted for MPA (period 1, 0.9; period 3, 2.49). The incidence of GPA (4.89 per 1000000 inhabitants per year) was three times higher than the total incidence of EGPA and MPA. The prevalence of AAV per 1000000 adult population increased from 35.92 in 2015 to 69.14 in 2021. 40 deaths were recorded during the study period, with a mean age at death of 65.2 (±13.03). AAV was associated with reduced life expectancy compared with the general population, especially when diagnosed at a young age. The SMRs for the total AAV cohort revealed a decreasing trend: 1.79 in period 1 and 1.67 in period 3. Conclusions AAV is associated with increased mortality. During the study period, the incidence of AAV was found to be stable, and the prevalence has increased. |
