Idiopathic pulmonary fibrosis (IPF) is a lung disease where scar tissue forms in the lungs, making it hard to breathe. As the disease progresses, the lung tissue becomes thickened and stiff, making it difficult for oxygen to pass into the bloodstream. The exact cause is still not fully understood, although it is believed to involve a combination of genetic and environmental factors. It primarily affects older adults. Most survive for about three to five years after diagnosis. Treatments, called antifibrotics aim to slow progression and improve quality of life. Despite the seriousness of the condition and poor prognosis until recently there hasn’t been much research. Until a decade ago there were no guidelines on how to diagnose Idiopathic Pulmonary Fibrosis. We conducted a prior study to understand how general practitioners (GPs) record Idiopathic Pulmonary Fibrosis and after observing changes in coding practices calculated updated incidence and prevalence . We hope through this study to develop a better understanding of disease survival and assess the impact of treatments on survival. We will used linked primary and secondary care data and mortality data to calculate the mortality rates of people with idiopathic pulmonary fibrosis and see how this has changed over time as well as explore what people with idiopathic pulmonary fibrosis die of and how this has changed over time. This will help us better understand how we can improve survival in this population.
Idiopathic pulmonary fibrosis (IPF) is a lung disease where scar tissue forms in the lungs, making it hard to breathe. People diagnosed with IPF have a historic median survival of less than 3-5 years from diagnosis. We conducted a prior study to understand how general practitioners (GPs) record IPF (ID number 20_000068) and from this derived four algorithms with varying accuracy from which to determine someone has a diagnosis. These 4 algorithms are: i) individuals with a diagnosis of pulmonary fibrosis of any aetiology (not necessarily IPF diagnosis) in Aurum and a primary or secondary discharge diagnosis of IPF in HES APC, known as ‘Aurum and HES’ ii) individuals with an evidence of at least one clinical code strongly indicative of an IPF diagnosis in Aurum, known as ‘Aurum narrow’ iii) individuals with a diagnosis of pulmonary fibrosis of any aetiology (not necessarily IPF diagnosis) in Aurum (evidence of at least one clinical code with a possible diagnosis of IPF) known as ‘Aurum broad’ and, iv) individuals discharged with a primary or secondary diagnosis of IPF in HES APC, known as ‘HES APC’.
In this study, we will use linked Aurum, hospital episode statistics inpatient data (HES APC) Office for national statistics (ONS) mortality data and deprivation data (IMD). We will investigate changes in survival and causes of death over the past 10 years using the definitions from the validation study. Each of the following aims will be assessed:
i) Determine median survival in patients with IPF
ii) Determine year-on-year all-cause mortality
iii) Investigate changes in causes of death
Understanding the causes of death and survival over time will better help us understand how these people are currently managed and will inform us whether treatment developments may have had an impact on the IPF field.
Our overall study period is from 1 January 2010 to the end of the available linked data. Our study period will include people who have a new diagnosis of IPF (incident cases). Findings from another study (ISAC protocol 20_000068) will be used to define 4 IPF study cohorts. Outcomes that will be assessed in these 4 IPF study cohorts are
1. Year-on-year survival over the study period
2. Year-on-year all-cause mortality
3. Change in causes of death over the study period
Jennifer Quint - Chief Investigator - Imperial College London
Rikisha Shah Gupta - Corresponding Applicant - Imperial College London
Ann Morgan - Collaborator - Imperial College London
Peter George - Collaborator - Royal Brompton Hospital
HES Admitted Patient Care;ONS Death Registration Data;Patient Level Index of Multiple Deprivation