Burden of illness associated with eosinophilic granulomatosis with polyangiitis: a systematic literature review and meta-analysis

Eosinophilic granulomatosis with polyangiitis (EGPA) is a rare disease associated with vascular inflammation and multisystem organ damage. The literature reporting EGPA incidence or prevalence is limited. We performed a systematic literature review and meta-analysis to describe the incidence, prevalence, and disease burden associated with EGPA. Real-world, observational, English-language studies in MEDLINE, MEDLINE In-Process, and Embase up to 6 June, 2019, were included. A single investigator screened all identified titles/abstracts and extracted data; an additional, independent investigator repeated the screening and validated the extracted data. A random-effects meta-analysis was conducted to generate pooled estimates for EGPA incidence and prevalence. Data from 100 eligible publications were extracted (32 with incidence/prevalence data, 65 with morbidity/healthcare resource data; 3 with both types of data). Significant evidence of between-study heterogeneity for reported incidence (p = 0.0013-0.0016) and prevalence (p = 0.0001-0.0006) estimates was observed. Global and European pooled estimates (95% confidence interval) of EGPA incidence were 1.22 (0.93, 1.60) and 1.07 (0.94, 1.35) cases per million person-years, respectively; global and European pooled estimates (95% confidence interval) for EGPA prevalence were 15.27 (11.89, 19.61) and 12.13 (6.98, 21.06) cases per million individuals, respectively. The proportions of patients experiencing relapses, or who had nasal polyps or severe asthma, varied considerably across studies. EGPA healthcare resource use was high, with inpatient admissions and emergency department visits reported for 17-42% and 25-42% of patients, respectively. Our results indicate that although global and European EGPA incidence and prevalence is low, the associated disease burden is substantial.