Mortality Risk Lower for IPF Patients Diagnosed More Recently, Study Suggests
Patients diagnosed with idiopathic pulmonary fibrosis (IPF) in more recent years appear to have a lower risk of mortality on a short-term basis than those diagnosed more than 10 years ago, a study has found.
According to the researchers, these differences in short-term mortality may be due to changes in IPF treatment, particularly the introduction of anti-fibrotic therapies and the discontinuation of corticosteroids.
Conducted by a team in Denmark, the study, “Changes in management of idiopathic pulmonary fibrosis: impact on disease severity and mortality,” was published in the European Clinical Respiratory Journal.
IPF is a progressive interstitial lung disease of unknown origin caused by the formation of scar tissue, known as fibrosis, in the lungs that make it harder for patients to breathe. The prognosis of IPF patients is usually poor, with a median survival of three to five years following diagnosis.
But, “since 2011, anti-fibrotic therapy has been available with the potential of slowing disease progression and increasing survival,” the researchers wrote.
To examine this further, they assessed and compared the survival and short-term mortality of two groups of IPF patients who were diagnosed in different decades, thus having access to different therapies.
“We hypothesized that better diagnostic strategies and increased awareness of IPF owing to the emergence of evidence-based therapies would result in earlier diagnosis and improved survival,” they wrote.
They reviewed the electronic medical records of patients diagnosed with IPF from 2011–2016 at the Aarhus University Hospital, and compared them with data from a second group of patients who had been diagnosed and treated at the hospital from 2003–2009.
The GAP-index — a staging tool that can estimate a patient’s prognosis based on his or her age, sex, and certain respiratory parameters — was used to divide patients into three categories of disease severity.
The 2011–2016 group was made up of 260 patients, including 205 men and 55 women, with a mean age of 72.6 years at diagnosis. All patients in this group had a high-resolution computed tomography (HRCT) scan of their lungs, and more than half (55%) were found to have the typical pattern of usual interstitial pneumonia (UIP) — an indicator of IPF.
Patients in this group had a mean forced vital capacity (FVC) of 80%, and a mean diffusing capacity for carbon monoxide (DLCO) of 44%. FVC measures the total amount of air a person is able to exhale after taking a deep breath, while DLCO measures how much oxygen is transferred from the lungs into the bloodstream.
Similarly, all 121 patients — 93 men and 28 women, with a mean age of 67.4 years at diagnosis — in the 2003–2009 group had an HRCT scan, and half of them also had the typical UIP pattern.
Statistical analyses found that FVC and DLCO were both predictors of mortality in these patients. However, the presence of a UIP pattern in HRCT scans was not.
Nearly half of the patients in both groups had moderate IPF and an intermediate risk of mortality (GAP II stage), and approximately a third had mild disease severity and a lower risk of mortality (GAP I stage).
“Disease severity at the time of IPF diagnosis in our study was unchanged between 2003–2009 and 2011–2016, which contradicts our hypothesis of earlier diagnosis,” the researchers wrote.
Among those diagnosed from 2011–2016, 80% of patients in GAP stage I, 73% in GAP stage 2, and 29% in GAP stage III were treated with anti-fibrotic therapies. Apart from palliative care in patients with very severe disease, corticosteroids or other immunosuppressants were not used in in this group.
In contrast, 85% of patients in the 2003–2009 group were treated with corticosteroids.
Analyses showed that patients in the 2011–2016 group tended to live for a longer period of time than those in the 2003–2009 group — a median survival of four versus 3.2 years.
Overall, one-year mortality was also found to be lower among those who had been diagnosed with IPF more recently, compared with patients who were diagnosed more than 10 years ago — 13% vs. 26%.
The same held true when considering only those with severe IPF (GAP stage III) who had a higher risk of mortality — 26% vs. 54% in patients in the 2003–2009 group.
“We saw a significant mortality decline in 2011–2016 … [which] was driven mainly by the decline in short-term mortality among patients with severe disease, and may be linked to the changes in treatment strategies towards limited use of corticosteroids as well as the introduction of antifibrotic therapy,” the researchers concluded.