Many patients in the UK have chronic obstructive pulmonary disease (COPD), a lung disease usually caused by smoking. Some COPD patients also have another lung condition, bronchiectasis. Bronchiectasis is a long-term condition where the airways of the lungs become widened, leading to a build-up of excess mucus that can make the lungs more vulnerable to infection. A common treatment for COPD to prevent symptoms and worsening of the disease, is inhaled steroids. However several studies have shown that inhaled steroids in COPD increase their risk of chest infections and pneumonia. As patients with both bronchiectasis and COPD contain higher amounts of bacteria living in the lungs, it may be expected that in these patients using inhaled steroids will result in an even higher risk of pneumonia. If such patients are at higher risk of pneumonia, doctors and patients should be aware of this as alternative medication options may need to be considered.
We will draw a cohort of COPD patients with incident or no use of inhaled steroids (ICS). From this cohort a nested case control study will be conducted. The exposure will be ICS use and the outcome will be hospitalised or death from pneumonia using Hospital Epidsodes Statistics & Office of National Statistics (primary outcome) and lower respiratory tract infections (secondary outcome). Cases will be matched 1:4 with controls by age, gender and GP practice. The cases and controls will be compared using simple descriptive analysis. Conditional multivariable logistic regression will be used to determine any association between the exposure (ICS use) and the outcome. Covariates considered in the models will include socioeconomic status (IMD), lung function, breathlessness score, oral corticosteroid use in past three years, BMI, vaccination (influenza and pneumococcal), asthma, cardiovascular disease, cerebrovascular disease, renal failure, rheumatic diseases, lung fibrosis, reflux, previous pneumonia, smoking, alcohol, and depression. Bronchiectasis will be considered as an interaction term. Analysis will be stratified by ICS drug type and timing of exposure. The aims and objectives will be to determine if ICS increases the risk of pneumonia in patients with COPD and bronchiectasis. Understanding the potential side effects of ICS is important for physicians and doctors.
Primary outcome = hospitalised/death pneumonia; secondary outcome = pneumonia (GP managed) or lower respiratory tract infection .
Chloe Bloom - Chief Investigator - Imperial College London
Chloe Bloom - Corresponding Applicant - Imperial College London
Anand Shah - Collaborator - Imperial College London
Andrew Ritchie - Collaborator - Imperial College London
Aran Singanayagam - Collaborator - Imperial College London
Sebastian Mitchell - Collaborator - Imperial College London
HES Admitted Patient Care;ONS Death Registration Data;Patient Level Index of Multiple Deprivation