In the UK, someone experiences a potentially life-threatening asthma attack every ten seconds, while every day three people die from asthma. Although some of these events could be prevented with daily inhaled corticosteroid (ICS) treatment, some patients continue to suffer from severe asthma despite good compliance to therapy.
A previous study conducted by the Observational and Pragmatic Research Institute (OPRI) found that patients with asthma and high blood eosinophil counts experience more severe exacerbations and have poorer asthma control.
The results suggest that this subpopulation of patients with asthma does not respond well to guideline-recommended therapy.
There is no evidence available that a step-up to high dose ICS would be effective in preventing asthma attacks in these patients.
Nevertheless, high ICS doses are frequently prescribed in real-life, exposing patients to the risk of adverse effects.
We aim to study the effectiveness of initiating patients with asthma and high blood eosinophil counts on high dose ICS to reduce exacerbation risk and to achieve asthma control.
This study may provide a rationale for alternative therapy options, such as biologic therapy targeting eosinophils, in patients with asthma who do not respond well to current guideline-recommended therapy.
Objective: to study the effectiveness of initiating patients with high blood eosinophil counts on high dose ICS to reduce exacerbation risk and to achieve asthma control.
Patients with asthma and high blood eosinophil counts who step-up to high dose ICS will be extracted from the Clinical Practice Research Datalink or the Optimum Patient Care Research Database (date is index date (ID)).
1. Patients who step-up from medium to high dose ICS will be matched to and compared with control patients on stable medium dose treatment during follow-up (Figure).
The ID of control patients will be chosen at exactly the same number of days after the date of blood eosinophil count recording as the matched step-up patient.
2. Patients who step up from low to high dose ICS will be matched to and compared with patients who step up from low to medium dose ICS.
Patients will be matched on the following characteristics assessed in the year prior to ID: timing and value of eosinophil count, number of exacerbations, ICS drug and dose, propensity score of high dose ICS assignment.
Survival and negative binomial regression analyses will be used to compare the rates of asthma exacerbations over 1 and 3 years of follow-up.
• Asthma exacerbations • Excessive short-acting bronchodilator use • Hospitalisations for asthma • Acute respiratory events
David Price - Chief Investigator - OPRI - Observational and Pragmatic Research Institute Pte Ltd
Marjan Kerkhof - Corresponding Applicant - OPRI - Observational and Pragmatic Research Institute Pte Ltd
Andrew Menzies-Gow - Collaborator - Royal Brompton Hospital
Derek Skinner - Collaborator - Research in Real Life ltd.( RiRl )
Gopalan Gokul - Collaborator - Astra Zeneca Inc - USA
Guy Brusselle - Collaborator - Ghent University Hospital
Janwillem Kocks - Collaborator - University Medical Centre Groningen
Javier Nuevo - Collaborator - Astra Zeneca Inc - USA
Rupert Jones - Collaborator - Plymouth University
Sarang Rastogi - Collaborator - Astra Zeneca Inc - USA
Trung Tran - Collaborator - Astra Zeneca Inc - USA
HES Admitted Patient Care