The number of cases of idiopathic pulmonary fibrosis (IPF) has continued to rise significantly in the first decade of the 21st century and could lead to more deaths than ovarian cancer, lymphoma, leukaemia, or kidney cancer, reveals research published ahead of print in the Thorax journal.
IPF is the most common of the pneumonias that happen without an apparent cause and previous studies have shown that incidence and deaths from the disease are rising in the UK and the USA.
However, there is currently no mandatory registration of IPF diagnoses in the UK or anywhere else in the world.
Researchers from the Nottingham Respiratory Biomedical Research Unit and the University of Nottingham set out to determine the trends in incidence of this disease.
The researchers used two different sets of data to investigate whether the incidence of pulmonary fibrosis in the 21st century was still growing in the UK.
These data were routine mortality data from the Office for National Statistics (ONS) between 1968 and 2008 and The Health Improvement Network (THIN), a computerised longitudinal primary care database recorded by UK GPs in 446 general practices.
Using the definition of idiopathic pulmonary fibrosis clinical syndrome (IPF-CS), they found that there were 56,675 deaths attributed to IPF-CS in England and Wales from 1968 to 2008. The number of recorded deaths increased from 479 in 1968 to 3,019 in 2008.
Annual death certificate recordings of the disease rose six-fold across the study period from 0.92 per 100,000 people in the 1968-1972 period, to 5.1 per 100,000 people in the 2006-2008 period.
Numbers of cases recorded in primary care rose by 35% from 2000 to 2008 with an overall incidence rate of 7.44 per 100,000 person years. Incidence was highest in men, the older population and in north-west England.
Using these figures, the researchers estimate that there are currently around 15,000 people in the UK with a diagnosis of the disease, and that 5,000 new cases will be diagnosed each year, with around 5,000 people with the disease dying.
This would mean more people in the UK dying each year from IPF-CS than from ovarian cancer, lymphoma, leukaemia, mesothelioma or kidney cancer.
The authors conclude: " At the moment, we do not understand what causes IPF-CS, why the incidence is on the rise or how best to treat individuals with this disease spectrum.
"It is clear that IPF-CS is an important public health problem and warrants more research investment."