Blood Eosinophil Levels and Severe Asthma Exacerbations Among Paediatric Patients with Asthma in the English Primary Care Setting

Date of Approval: 
2018-04-26 00:00:00
Lay Summary: 
Asthma is a common disease affecting the airways of the lungs and is characterised by recurrent episodes of shortness of breath known as exacerbations. The purpose of this study is to describe the characteristics of paediatric patients (ages 6-17) with asthma in England and to provide insight on the clinical care they receive. The study will focus on paediatric patients with asthma as defined by medication use, blood tests (eosinophil levels), and/or frequency of severe asthma exacerbations. Four asthma cohorts reflecting escalating levels of asthma severity and control will be created: 1) Asthma cohort - all paediatric patients treated with an asthma medication; 2) Severe asthma cohort - paediatric patients classified as having severe asthma based on the asthma treatments received; 3) Severe refractory asthma cohort - paediatric patients classified as having severe refractory asthma according to the asthma treatments received and the number of asthma exacerbation episodes experienced; and 4) Severe refractory eosinophilic asthma cohort - paediatric patients classified as having severe refractory eosinophilic asthma based on the asthma treatments received, number of asthma exacerbations and elevated blood eosinophil levels. This study will provide up-to-date information on the characteristics of these paediatric patient cohorts in England and insight on the clinical care they receive.
Technical Summary: 
Asthma-related exacerbations remain a significant burden on the healthcare system and can be described as an acute episode of progressively worsening shortness of breath, wheezing, and chest tightness that results in decreased lung function.1 A severe asthma exacerbation can be defined as: (1) treatment with an initial or increased dose of OCS, (2) an accident and emergency department (A&E) visit, and/or (3) a hospital admission.2 Eosinophilic asthma, recognisable due to its increased levels of blood eosinophils, has been associated with diminished lung function, airway inflammation, uncontrolled symptoms, and higher amounts of exacerbations than non-eosinophilic asthma.3,4 Evidence suggests that the association between increased eosinophils and more numerous exacerbations may be even more apparent in paediatric patients than in adults.5 The current study will describe the background epidemiology and health care utilization in the four paediatric (aged 6-17 years) asthma cohorts in terms of medications, blood eosinophil levels, and/or frequency of severe asthma exacerbations.
Health Outcomes to be Measured: 
Asthma exacerbations (i.e., asthma-related general practitioner (GP)/hospital visits) - asthma-related healthcare resource utilization - asthma treatments
Application Number: 
18_108
Collaborators: 

Melissa Van Dyke - Chief Investigator - GSK
Mugdha Gokhale - Corresponding Applicant - GlaxoSmithKline - UK
Lee Evitt - Collaborator - GSK
Sarah Rabhi - Collaborator - Not from an Organisation
Takako Hattori - Collaborator - GSK

Linkages: 
HES Accident and Emergency;HES Admitted Patient Care;HES Outpatient