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

Abstract

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. Key points • We performed a systematic literature review and meta-analysis of real-world, observational studies describing the incidence, prevalence, and disease burden associated with eosinophilic granulomatosis with polyangiitis (EGPA). • Based on meta-analysis data from 35 eligible studies reporting incidence and prevalence, the incidence and prevalence of EGPA were low (globally 1.22 cases per million person-years and 15.27 cases per million individuals, respectively). • Among the 49 studies with morbidity and/or healthcare resource data, most reported a large proportion of patients with EGPA relapses and comorbidities of nasal polyps and severe asthma. • Healthcare resource use was also high among patients with EGPA in these studies, with inpatient admissions and emergency department visits reported for 17-42% and 25-42% of patients, respectively. Taken together, these data indicate the substantial disease burden associated with EGPA.

Keywords: Burden; Eosinophilic granulomatosis with polyangiitis; Incidence; Meta-analysis; Prevalence; Systematic review.

Fig. 1

PRISMA flow diagram outlining the study selection process. Three publications (reporting the results of 3 studies) were included in both the incidence/prevalence reporting and the morbidities/HCRU reporting of the SLR. EGPA, eosinophilic granulomatosis with polyangiitis; HCRU, healthcare resource utilisation; PRISMA, Preferred Reporting Items for Systematic Reviews and Meta-Analyses; SLR, systematic literature review

Fig. 2

Estimated incidence of EGPA, globally and in Europe. * tau = 0.43, I² = 71.23%, p = 0.0013; ^† tau = 0.43, I² = 66.5%, p = 0.0016. The global meta-analysis RE model included all (European and non-European) studies; tau values describe the estimated standard deviation of underlying true effects across studies; I² values represent the total proportion of variance in estimates that is due to heterogeneity. CI, confidence interval; EGPA, eosinophilic granulomatosis with polyangiitis; MA, meta-analysis; RE, random effects; UK, United Kingdom; US, United States

Fig. 3

Estimated prevalence of EGPA, globally and in Europe. * tau = 0.68, I² = 81.76%, p = 0.0001; ^† tau = 0.36, I² = 90.56%, p = 0.0006. The global meta-analysis RE model included all (European and non-European) studies; tau values describe the estimated standard deviation of underlying true effects across studies; I² values represent the total proportion of variance in estimates that is due to heterogeneity; the two prevalence estimates from Bell 2018 represent data from the same study collected separately from two different databases. CI, confidence interval; EGPA, eosinophilic granulomatosis with polyangiitis; MA, meta-analysis; RE, random effects