Idiopathic pulmonary fibrosis (IPF) is a chronic disease of unknown origin that causes scarring of the lungs. It is mainly a disease of older age and is more common in men. There is no cure and prognosis is generally poor; once someone has got a diagnosis of IPF, they tend to only live for another 3–5 years. The majority of people with IPF have several other medical problems or “comorbidities”. A high proportion have acid indigestion (or reflux disease); some also have other lung diseases, for example, lung cancer or chronic obstructive pulmonary disease (COPD). Because of the high frequency of comorbidities and also because most people with IPF first present to their GP with very ordinary, non-specific symptoms – cough and breathlessness – misdiagnoses and delays in IPF diagnosis are commonplace. In practice, this means that GPs often mistake the early signs of IPF as COPD or asthma and prescribes inhaled corticosteroids (ICS) to treat patients’ respiratory symptoms. Also, many IPF patients are routinely prescribed antacids, even if they do not have obvious reflux disease. However, evidence is now emerging that both ICS and antacid therapies might not actually be helping patients with IPF as much as we previously thought; worse still there is some suggestion that regular, prolonged use may be causing harm. The aim of this study is therefore to determine whether use of ICS and antacids is associated with an increased risk of adverse respiratory outcomes, in particular pneumonia, in people with IPF.
Idiopathic pulmonary fibrosis (IPF) is a chronic, fibrotic interstitial lung disease of unknown aetiology. It is characterised by progressive fibrosis or scarring of the lungs. The first symptom of IPF is frequent coughing and shortness of breath, symptoms which are shared with chronic obstructive pulmonary disease (COPD), late-onset asthma, and gastro-oesophageal reflux disease (GORD), all of which are all common co-morbidities in IPF. This situation often leads late diagnosis of IPF and, ultimately, delays in starting appropriate treatment. There is a growing body of evidence suggesting that inhaled corticosteroids (ICS) or antacids may actually worsen lung function decline in IPF and may even be associated with increased risk of pneumonia or death. To date, few studies have investigated patterns of ICS and antacid use in the IPF patient population, and as far as we are aware no study has examined pneumonia outcomes in people with IPF who have been prescribed ICS-containing-inhalers to reduce their respiratory symptoms and antacids to treat comorbid GORD.
We hypothesize that prolonged ICS and antacid use leads to poor outcomes in patients with IPF. We aim to use the HES-APC and ONS-linked CPRD Aurum data to describe the proportion of patients with IPF who are treated with ICS and antacids (especially proton pump inhibitors or PPIs) over a recent10-year period (2010–2020). Secondly, we will use a multivariate Cox proportional hazards regression or Poisson regression models to explore the association between use of ICS and antacids and the risk of respiratory-related outcomes, (as appropriate) including pneumonia hospitalisation and IPF-mortality in a cohort of patients with IPF. HES APC will be used to determine hospitalisations and ONS to determine mortality. This will be of public health benefit as it will provide infromation on whether ICS and PPIs lead to poorer outcomes.
Descriptive analysis
• Proportion of patients prescribed ICS/antacids prior to diagnosis of IPF (with and without co-diagnoses of COPD/GORD)
• Proportion of patients who continue with ICS/antacid therapy post a diagnosis of IPF (with and without co-diagnoses of COPD/GORD)
Primary outcome measure:
• Mortality (all cause, and IPF-related)
Secondary outcome measures:
• Hospitalisation (all cause, respiratory-related, community-acquired pneumonia)
• Rate of lower respiratory tract infections or pneumonia (GP treated events)
Jennifer Quint - Chief Investigator - Imperial College London
Ann Morgan - Corresponding Applicant - Imperial College London
Georgie Massen - Collaborator - Imperial College London
Gisli Jenkins - Collaborator - Imperial College London
Hannah Whittaker - Collaborator - Imperial College London
Iain Stewart - Collaborator - Imperial College London
Peter George - Collaborator - Royal Brompton Hospital
Qiuyi Li - Collaborator - Imperial College London
Georgie Massen - Collaborator - Imperial College London
HES Admitted Patient Care;ONS Death Registration Data;Patient Level Index of Multiple Deprivation