Eosinophilic granulomatosis with polyangiitis (EGPA), formerly called Churg-Strauss syndrome, is a rare condition characterised by blood vessel inflammation. This inflammation can restrict blood flow to organs and tissues, sometimes permanently damaging them. The most common presenting features of EGPA are asthma, and nasal & sinus symptoms. EGPA is characterised by elevated white blood cell counts called eosinophils. Complications, which depend on the organs affected, can include peripheral nerve damage, heart disease and kidney damage among others.
EGPA varies greatly from person to person, with some cases becoming progressively worse. While some people have only mild symptoms, others have severe or life-threatening complications. The prognosis of patients with EGPA has improved significantly since the widespread use of systemic corticosteroids and immunosuppressive agents for patients with more severe disease. However, there is still a lack of knowledge of the disease resulting in diagnostic delay and unmet medical needs.
This study will describe the people with EGPA, the treatments they receive, the complications of their condition and how they use the health system in England. The results of this study will help to fill the gaps in our knowledge of EGPA patients in England and to understand the areas for improvement in their care.
The aim of this study is to quantify the incidence and prevalence of EGPA in England as well as to describe the patient journey, treatment patterns and healthcare resource use and treatment costs of EGPA patients in England from 2006 to 2020.
The primary study population will be all active EGPA cases in the Clinical Practice Research Datalink (CPRD) Aurum and Hospital Episodes Statistics (HES) Admitted Patient Care (APC) datasets between 1 January 2006 and 28 February 2020. In this population the objectives will be to describe the characteristics of patients, describe the prescription rates of EGPA and asthma medications, describe clinical outcomes at baseline, describe the mortality rate and primary causes of death, to compare the all-cause and EGPA-related healthcare resource use (HCRU) and costs in EGPA patients against the general population and uncontrolled severe asthma patients. Analyses will be repeated with a sub-sample of this population similar to the one used in the MANDARA clinical trial on efficacy and safety of benralizumab in EGPA compared to mepolizumab.
In addition, a cohort of newly diagnosed (incident) EGPA patients will be analysed to explore the patient journey before and after diagnosis, describe the drug therapy, the clinical outcomes at different time points and estimate the HCRU and costs in EGPA patients by studying all‐cause and EGPA-related healthcare resource use before and after diagnosis.
This study will be mainly descriptive. HCRU will be described by the rates of usage of each resource type. HCRU rates will be computed firstly as overall yearly rates for the period, and afterwards modelled by time through a conditional Poisson regression analysis.
Prevalence and incidence
Drug Therapy:
Prescribing rates; Medication regimens (duration and dose), cumulative dose of steroid use, steroid tapering; rescue therapy use; medication during pregnancy
Clinical outcomes:
Prognosis (Five Factor Score); EGPA events (complications) in primary or secondary care; Persistent vasculitic damage (complications) in primary or secondary care; Nasal Polyps, Comorbidities, Drug toxicity events; Disease status; all-cause mortality; primary cause of death
HCRU outcomes:
hospitalisations; primary care visits, all-cause A&E admissions; all-cause outpatient visits; length of hospital stay; length of ICU stay, number of inpatient procedures; GP prescriptions;
Cost outcomes:
Primary care visits; Days in Hospital; Outpatient visits (all cause only); A&E admissions (all cause only); GP prescription costs; Total annual costs of all HCRU
Paul Dolin - Chief Investigator - AstraZeneca Ltd - UK Headquarters
Bélène Podmore - Corresponding Applicant - OXON Epidemiology - Spain
Alessandra Lacetera - Collaborator - OXON Epidemiology - Spain
Ana Cunado Moral - Collaborator - OXON Epidemiology - UK
Anat Shavit - Collaborator - AstraZeneca Ltd - UK Headquarters
Cono Ariti - Collaborator - OXON Epidemiology - Spain
Ernesto Garcia - Collaborator - OXON Epidemiology - Spain
Pablo Suárez Sánchez - Collaborator - OXON Epidemiology - Spain
Ruth Owen - Collaborator - OXON Epidemiology - Spain
Salman Siddiqui - Collaborator - Imperial College London
Ernesto Garcia - Collaborator - OXON Epidemiology - Spain
HES Accident and Emergency;HES Admitted Patient Care;HES Outpatient;ONS Death Registration Data;Patient Level Index of Multiple Deprivation