Pneumonia is common, and people with lung diseases such as asthma may be at higher risk than the general population in terms of getting pneumonia. It is also possible that some treatments used to treat asthma, may contribute to the increased pneumonia risk. In other respiratory diseases, such as chronic obstructive pulmonary disease, use of inhaled steroids have been shown to increase the risk of pneumonia. It is not clear if inhaled steroids also increase the risk of pneumonia in people with asthma. We will investigate that in this study by firstly looking at risk of getting pneumonia in people with and without asthma. Then, in people with asthma we will look at whether being prescribed an inhaled steroid increases pneumonia risk by comparing the number of times patients develop pneumonia in people with asthma on and not on an inhaled steroid. We will also compare different inhaled steroids in order to investigate if there are differences regarding the type of inhaled steroid and their association to pneumonia
We will identify a cohort of patients with current asthma (using validated Read codes) and a random sample of the general population that do not have asthma, between 2006 and 2017. Patients will be aged 5 to 55 years, and will not have chronic obstructive pulmonary disease (similar disease that also uses same treatments). We will use a Poisson regression model to estimate the association between asthma, inhaled corticosteroids (ICS) and first hospitalised community acquired pneumonia (CAP). The exposure will be categorised according to asthma or not, and ICS dose (this will help to identify a dose response if there is one). We will adjust for multiple potential confounders (including age, gender, smoking, body mass index, use of immunosuppressives and diabetes mellitus). We will also carry out additional analyses to compare patients on the same ICS dose but with differing asthma severity (defined by their additional asthma maintenance medications), and compare patients on three commonly used different ICS drugs (beclometasone, fluticasone and budesonide). As the outcome is an event that occurs in secondary care we will only include patients with linked HES data.
Pneumonia hospitalisation
Mortality
Jennifer Quint - Chief Investigator - Imperial College London
Chloe Bloom - Corresponding Applicant - Imperial College London
Christer Janson - Collaborator - Imperial College London
Debbie Jarvis - Collaborator - Imperial College London
HES Admitted Patient Care;ONS Death Registration Data;Practice Level Index of Multiple Deprivation