Approximately one in nine people in the UK have asthma and the vast majority are managed within primary care without specialist care. Asthma attacks are acute or subacute episodes, which are characterized by a progressive increase in one or more typical asthma symptoms (shortness of breath, coughing, wheezing or tightness of the chest). These asthma attacks typically require urgent treatment, and can be life-threatening. Asthma guidelines across the world recommend daily inhaled drugs for symptomatic asthma patients. In addition they also recommend treatments that are not regular inhaled drugs including patient education on what asthma is and how patients can manage it themselves, flu vaccination, ways to stop smoking for smokers and regular reviews by doctors. We wish to see how often these non-drug managements are provided in primary care and if they affect a patients risk of developing an asthma attack. Other factors have also been shown to increase the risk of asthma attacks such as asthma severity, gender, age and smoking history. These will also be taken into account when assessing if non-drug treatments are associated with reducing asthma attacks or not.
Asthma patients will be identified from CPRD using a validated method. CPRD patients will be linked to their HES records to identify asthma attacks treated in both primary and secondary care. The annual incidence of multiple non-pharmacological asthma interventions will be measured between 2004 and 2018 and stratified by patient characteristics including age, gender and asthma severity. These will include asthma management plan, an annual asthma review, an inhaler technique check, smoking cessation where appropriate and influenza vaccination.
To determine the association between non-pharmacological interventions and asthma exacerbations an open cohort study will be carried out. Patients will be followed-up for one year after each intervention and rates of exacerbations will be measured using Poisson model. Both time to first analysis and multiple events (using repeated measures) will be assessed. Exposure will be each intervention and adjusted for known measurable confounders including demographics, clinical characteristics, medication adherence and healthcare utilisation.
1. Annual incidence of each non-pharmacological intervention
2. Stratified incidence by certain patient characteristics
3. Crude and adjusted exacerbation rate ratios
Jennifer Quint - Chief Investigator - Imperial College London
Chloe Bloom - Corresponding Applicant - Imperial College London
HES Accident and Emergency;HES Admitted Patient Care;ONS Death Registration Data;Patient Level Index of Multiple Deprivation