Idiopathic pulmonary fibrosis (IPF) frequently is diagnosed late, following other respiratory diagnoses and hospitalizations, according to study findings published in BMC Pulmonary Medicine.
Investigators sought to develop a timeline reflecting the diagnosis and treatment of IPF in the US. They therefore conducted a retrospective cohort analysis, using data from the Center for Medicare Services Fee for Service database. Participants were adult patients aged 50 years and older who had their first coded clinical diagnosis of IPF from January 1, 2014, to December 31, 2019.
The variables of interest at the initial IPF diagnosis included age, sex, race/ethnicity, region of residence, and history of smoking. Respiratory-related diagnoses and hospitalizations were evaluated at baseline and after IPF diagnosis.
The analysis included 44,891 patients; they had a mean (SD) age of 78.8 (5.4) years, 51% were female, and 93% were White. The percentage of patients diagnosed with IPF was relatively stable from 2014 to 2019, with about 15% to 20% of participants diagnosed each year.
Of the cohort, 98% of patients with IPF had other initial respiratory diagnoses before their initial IPF diagnosis. Upper respiratory infections (47%), acute bronchitis (13%), other upper respiratory disease (10%), chronic obstructive pulmonary disease and bronchiectasis (7%), and pneumonia (6%) were the most common respiratory-related diagnoses.
The patients had an average length of time from initial respiratory diagnosis to clinical IPF diagnosis of 990 days or 2.7 years and an average time from initial respiratory-related hospitalization to IPF diagnosis of 786 days or 2.2 years. Most participants (56.6%) had a respiratory-related hospitalization before being diagnosed with IPF, and many had additional hospitalizations after their IPF diagnosis (71.6%).
Antifibrotic therapy was used by 10.3% of patients with IPF during their disease course. The age group with the highest use of antifibrotic agents was those aged 65 to 74 years (15.1%). The patients with IPF were treated an average of 220 days or 7.3 months overall, and 24.6% did not refill their antifibrotics after their first prescription.
Oxygen therapy was used by 56% of the cohort at some point during their disease course, and 37% received oxygen before their IPF diagnosis. The average survival after oxygen initiation was 3.03 (median, 2.47) years.
Survival decreased each year after respiratory hospitalizations, with about a 50% survival rate 2 years after an initial respiratory-related hospitalization. The median survival time was 2.80 years after the coded IPF diagnosis.
Lung transplantations occurred in 0.28% of patients after their IPF diagnosis.
Limitations include use of a claims-based cohort dataset, along with researchers’ inability to review clinical notes and records to determine whether IPF was considered earlier than when the code appeared in the system.
“Our retrospective cohort demonstrates that IPF is often diagnosed late, usually
preceded by other respiratory diagnoses and hospitalizations. Use of available therapies is low and outcomes remain poor,” the study authors concluded. “We hope to reduce the delay to IPF diagnosis and treatment initiation by increasing the awareness of care of IPF patients and by enhancing education for providers on the appropriate diagnostic approach.”
Herberts MB, Teague TT, Thao V, et al. Idiopathic pulmonary fibrosis in the United States: time to diagnosis and treatment. BMC Pulm Med. 2023;23(1):281. doi:10.1186/s12890-023-02565-7