Asthma is a disease that affects the lungs. Symptoms may include coughing and feeling out of breath. With over 12% of the population diagnosed with asthma, the United Kingdom has one of the highest asthma rates in the world. Almost 70% of all asthma deaths are preventable in the United Kingdom. Meanwhile, the United Kingdom’s National Health Service spends more than £1 billion per year on treating asthma. A 2021 policy paper on the Government’s Life Sciences Vision highlighted the need to tackle asthma as one of the leading causes of disease and death.
Differences in wealth may impact asthma. The gap between the richest and poorest has worsened over the last 15 years. One important area to study is which factors drive differences in wealth. These factors impact people with asthma the most. We will use general practice and hospital records to look for differences in people with asthma. We will look at people in different positions in society within England from 2010 onwards.
We will look to see if there are differences in age, sex, and ethnicity. We will also look for differences in patients with other diseases. Patients with asthma may also suffer from these diseases. This research will help tackle why people with asthma in England have different experiences depending on their income.
Asthma is a chronic respiratory condition characterised by coughing, wheezing, chest tightness and breathlessness, which, if severe, can be debilitating. The UK has one of the highest rates of asthma prevalence worldwide, with inequalities worsening over the last decade. Meanwhile, the UK economy has spent over £1 billion annually on treating and managing asthma. COVID-19 has brought respiratory health, including asthma, to the forefront of public health policy. Few studies have investigated the role of inequalities in asthma care and outcomes. A study in 2021 assessed the association between socioeconomic status and asthma, albeit limited to Wales, before COVID-19 and at the Index of Multiple Deprivation (IMD) quintile level. Building on a previous eRAP 23_003658, we will analyse the association within the English asthma population from 2010 onwards, focussing on the domains that comprise IMD. We will link CPRD Aurum primary care data with Hospital Episode Statistics Admitted Patient Care (exploring hospitalisations, asthma exacerbations, intensive care visits, length of stay, and re-admission), Hospital Episode Statistics A&E (exploring A&E visits and cause-specific A&E visits), ONS Death Registration (exploring mortality). The exposures will be IMD and its domains in quintiles, and the outcomes will be asthma diagnosis, asthma management and asthma outcomes. As a result, policymakers can allocate resources and deliver interventions that improve inequalities in asthma outcomes.
We will fit count regression models, namely negative binomial multilevel models, to estimate the incidence rate ratio for variables that represent the count of asthma-related events within a given IMD quintile compared with the least deprived quintile. We will fit logistic and survival models to determine the factors associated with asthma-related death. All models will be adjusted for relevant covariates, including sex, age, ethnicity, and other risk factors.
We will measure the following variables across the pathway during the follow-up period:
1. Asthma diagnosis:
• Time to asthma diagnosis
• Place of diagnosis
• Asthma severity upon diagnosis
2. Asthma management:
• Asthma-related health service utilisation (GP and hospital visits)
• Asthma GP consultations defined as 1 or more SNOMED CT codes for asthma-related contact with primary care professionals.
• Prescribed medications and treatment
• Attendance at annual asthma reviews, comprising inhaler technique and the Royal College of Physicians 3 Questions.
• Delivery of personalised action plans
3. Asthma outcomes:
• Asthma emergency department attendance
• Asthma admissions including all, emergency, length of stay, and re-admissions
• Asthma ICU admission
• Asthma exacerbations
• All-cause and cause specific mortality including asthma-related death
Jennifer Quint - Chief Investigator - Imperial College London
Zakariah Gassasse - Corresponding Applicant - Imperial College London
Constantinos Kallis - Collaborator - Imperial College London
Hannah Whittaker - Collaborator - Imperial College London
HES Accident and Emergency;HES Admitted Patient Care;ONS Death Registration Data;Patient Level Index of Multiple Deprivation;Patient Level Index of Multiple Deprivation Domains