The Burden of Progressive-Fibrosing Interstitial Lung Diseases

Abstract

Despite conventional treatment, a proportion of interstitial lung disease (ILD) patients develop a progressive phenotype known as “fibrosing ILD with a progressive phenotype” (PF-ILD), characterized by worsening respiratory symptoms, decline in lung function, and early mortality. This review describes the epidemiology, and the humanistic and economic burden of PF-ILDs other than idiopathic pulmonary fibrosis (non-IPF PF-ILD). A structured review of the literature was conducted, using predefined search strategies in Ovid MEDLINE and EMBASE, and supplemented with gray literature searches. The search identified 3,002 unique articles and an additional 3 sources were included from the gray literature; 21 publications were included. The estimated prevalence of non-IPF PF-ILD ranges from 6.9 to 70.3/100,000 persons and the estimated incidence from 2.1 to 32.6/100,000 person-years. Limited evidence demonstrates that PF-ILD has a significant impact on patients' quality of life, affecting their daily lives, psychological well-being, careers, and relationships. PF-ILD is also associated with significant economic burden, demonstrating higher healthcare resource use and direct costs compared with the non-progressive phenotype, and indirect costs, which include job losses. This review indicates that PF-ILD places a considerable humanistic burden on both patients and caregivers, and a substantial economic burden on healthcare systems, patients, and society.

Works in Progress: Using Administrative Data to Estimate the Prevalence of Progressive Fibrosing Interstitial Lung Disease

“…After applying their carefully crafted algorithm, Singer and colleagues estimated a prevalence range for non-IPF progressive fibrosing ILD of 12.14–29.05 per 10,000 among Medicare Part D enrollees between 2015 and 2019. This estimate is significantly higher than those obtained in previous analyses in Europe and the United States (1.94–7.8 per 10,000) ( 5 ) and estimates of 0.89–2.36 per 10,000 among commercial insurance enrollees found in this study ( 6 ).…”

“…Rather than focusing solely on the underlying etiology of a patient’s ILD, recent evidence highlights the importance of also considering the shared pathophysiology across the progressive fibrotic disease spectrum ( 2 ), as well as the common benefits provided by antifibrotic therapy when used in patients with varying causes of pulmonary fibrosis ( 3 , 4 ). Yet, in part because progressive fibrosing ILD is a novel concept for which treatment was only recently approved, and also because it is a phenotype that can affect any of a heterogeneous group of distinct lung diseases, data regarding the prevalence of progressive fibrotic ILD (outside of idiopathic pulmonary fibrosis [IPF]) are scarce and highly variable ( 5 ).…”

“…In summary, the study by Singer and colleagues is an admirable demonstration of the potential for creative analysis using administrative data to estimate the real-world prevalence of non-IPF forms of progressive fibrotic ILD. Accurate estimates of the prevalence of progressive fibrotic diseases are urgently needed to improve prognostic counseling for patients and to allow fair allocation of resources given the association of progressive fibrosing ILDs with significantly higher healthcare resource usage ( 5 ). Validation of the algorithm designed for this study would certainly strengthen the authors’ inferences, but this should not detract from the importance of such research using large administrative claims data sets to study ILD epidemiology and outcomes, for which clinical trials and cohort studies are ill suited.…”

A case of welder's pneumoconiosis treated with corticosteroid followed by nintedanib

“…Recently, progressive fibrosing interstitial lung disease (PF-ILD) has been redefined as a new clinical syndrome with similar genetics, pathophysiology, and a natural history to idiopathic pulmonary fibrosis (IPF) [ 9 ]. Novel uses of antifibrotic therapy are emerging due to a paucity of evidence-based treatments for multiple ILD subtypes.…”

Expression profiles of nintedanib-targeting molecules in progressive fibrotic interstitial lung diseases (non-IPF-PF) and IPF

“…The pathogenesis of IPF is known to overlap with the pathogenesis of progressive brosis in non-IPF-PF, such as diseases associated with systemic sclerosis (SSc)(6-9). non-IPF-PF includes interstitial lung diseases such as chronic hypersensitivity pneumonia (cHP), ILD associated with connective tissue disease (CTD), and asbestosis (10,11).…”