Asthma is a disease which affects the airways of the lungs. Asthma symptoms include coughing, wheezing and shortness of breath. Globally in 2019, there were approximately 262 million people with asthma and the condition caused around 450,000 deaths. Inhaled Corticosteroid / Long Acting Beta-2 Agonist (ICS/LABA) is a medication commonly used by people with asthma to help keep their airways open and prevent symptom flare-ups. People with poorly controlled asthma (e.g. those who experience regular symptoms, broken sleep and interruptions to their daily living) can experience symptom flare-ups and many rely on temporary medication, known as reliever therapy, to ease symptom flare-ups. Poorly controlled asthma is often a result of people taking asthma medications incorrectly or living with other conditions affecting their asthma.
Symptom flare-ups and reliance on reliever therapy are linked with reduced quality of life, so factors that increase a person’s risk for flare-ups are important to understand. Factors known to increase the risk of poorly controlled asthma include old age, smoking history, depression and other related conditions. However, there is little evidence in England on how these factors interact with each other and increase the chance of symptom flare-ups or reliance on reliever therapy in people prescribed an ICS/LABA. Observing interactions between these factors will provide information on people with similar characteristics which can be used to tailor treatment management for people with asthma in clinical practice.
Aim: To understand treatable traits of adults with asthma newly initiating twice daily single inhaler ICS/LABA therapy in England. Exacerbations and over-reliance on reliever therapy are linked with reduced quality of life in asthma, so risk factors are important to understand.
Objectives: To: i) identify baseline socio-demographics and clinical characteristics of adults with asthma that are predictors of exacerbation or over-reliance on reliever therapy after initiating twice daily single inhaler ICS/LABA therapy; ii) describe treatment characteristics following initiation of twice daily single inhaler ICS/LABA therapy among risk groups; and iii) describe socio-demographic, clinical and treatment characteristics of adults with asthma prescribed Seretide® or Symbicort®, respectively.
Methods: Retrospective analysis of longitudinal healthcare data in England utilising linked primary and secondary care data from Clinical Practice Research Datalink (CPRD) Aurum and Hospital Episode Statistics (HES) datasets, respectively.
Index criteria: Asthma diagnosis; twice daily ICS/LABA dual therapy
Covariates: Baseline characteristics (age, gender, region, ethnicity, deprivation, BMI, smoking status, eosinophil levels, comorbidities, Charlson Comorbidity Index (CCI), peak expiratory low rate (PEFR), forced expiratory volume, dyspnea scale score, asthma symptoms, history of asthma-related exacerbation, history of over-reliance on reliever therapy, previous maintenance therapy, previous oral corticosteroid use (OCS use), primary care consultations and hospitalizations) and treatment characteristics (ICS/LABA brand, treatment add-on or switches, duration on treatment, daily average ICS/LABA dose, dose change, ICS/LABA adherence, ICS/LABA frequency, ICS/LABA device type)
Outcomes: Asthma exacerbation; over-reliance on reliever therapy.
Data analysis: People will be classified based on binary outcome status (asthma exacerbation and over-reliance on reliever therapy). Demographics and clinical characteristics will be assessed in relation to outcome status using a supervised learning method. A pragmatic approach will then be used to select most important predictors of outcomes in order to form homogeneous clusters via an unsupervised learning algorithm. Treatment characteristics will be described within each homogeneous cluster.
Asthma exacerbation; over-reliance on reliever therapy.
Mohamed Hamouda - Chief Investigator - GlaxoSmithKline - UK
Elke Rottier - Corresponding Applicant - Adelphi Real World
Arunangshu Biswas - Collaborator - GSK India Global Service Private Limited
Jennifer Quint - Collaborator - Imperial College London
Lucinda Camidge - Collaborator - Adelphi Real World
Poppy Payne - Collaborator - Adelphi Real World
Robert Wood - Collaborator - Adelphi Real World
Rosie Wild - Collaborator - Adelphi Real World
Sarah Law - Collaborator - Adelphi Real World
HES Accident and Emergency;HES Admitted Patient Care;Patient Level Index of Multiple Deprivation