Incidence and Prevalence

Latest Global Estimates of Idiopathic Pulmonary Fibrosis Incidence and Prevalence

Idiopathic pulmonary fibrosis (IPF) has emerged as an important public health problem requiring global coordination of data on incidence and mortality. Recent epidemiological studies provide valuable insights into the global burden of this chronic interstitial lung disease.

Global Incidence

According to a 2021 systematic review, a conservative incidence range of 3-9 cases per 100,000 per year is estimated for Europe and North America from studies published from 2000 onwards. This review analyzed 34 studies from 21 countries spanning 1968-2012, with 28 studies reporting incidence data.

Regional variations exist, with incidence lower in East Asia and South America compared to Europe and North America. In the USA, annual incidence was estimated at 6.8-8.8 per 100,000 population using narrow case definitions and 16.3-17.4 per 100,000 population using broad case definitions. European annual incidence ranged between 0.22 and 7.4 per 100,000 population.

More specific regional data shows: - In Taiwan, annual IPF incidence rates between 0.9 and 1.6 cases per 100,000 persons after 2000 - In Poland's Radom region, a crude incidence rate of 2.5/100,000 adults - In Poland's Silesian Voivodeship, standardized incidence rates of 2.9-3.8/100,000 population during 2006-2010

The U.S. Veterans population shows significantly higher rates, with annual incidence increasing from 73 cases per 100,000 person-years in 2010 to 210 cases per 100,000 person-years in 2019 using a narrow case definition.

Global Prevalence

Prevalence data varies by region and age group. In the United States, using broad case-finding criteria, prevalence ranged from 4.0 per 100,000 persons aged 18-34 to 227.2 per 100,000 among those 75 years or older. With narrow criteria, prevalence ranged from 0.8 to 64.7 per 100,000 persons.

When extrapolated to the overall United States population, prevalence was estimated to be 42.7 per 100,000 using broad criteria and 14.0 per 100,000 using narrow criteria.

Recent data shows: - In the U.S. Veterans population, prevalence increased from 276 cases per 100,000 in 2010 to 725 cases per 100,000 in 2019 - In USA adults 18-64 years, annual cumulative prevalence increased from 13.4 cases per 100,000 persons in 2005 to 18.2 cases per 100,000 persons in 2010 - In Taiwan, prevalence rates more than doubled from 2000 to 2007, from 2.8 to 6.4 cases per 100,000 persons using broad definition - In Poland's Radom region, ten-year prevalence rates were 25.5 per 100,000 adults

Trends and Risk Factors

The majority of studies showed an increase in incidence over time, with rates becoming more similar across countries. IPF is probably more common in the United States than previously reported and its incidence is increasing worldwide.

The prevalence of IPF is highest in elderly patients aged ≥75 years. Risk factors associated with IPF among Veterans included older age, White race, tobacco use, and rural residence. Men older than 75 years had markedly higher incidence and prevalence rates than other groups in Taiwan.

IPF incidence is similar to that of conditions such as stomach, liver, testicular and cervical cancers, highlighting its significance as a public health concern.

Recent Studies

Recent Studies for Idiopathic Pulmonary Fibrosis

Historical Eye Study (2023)

• Intervention: Antifibrotic therapy

• Efficacy outcomes:

• Significant reduction of all-cause mortality (ATE coeff -0.23, SE 0.04, p < 0.001)

• Significant reduction in acute exacerbations (ATE coeff -0.15, SE 0.04, p < 0.001)

• Significant reduction in hospitalizations (ATE coeff -0.15, SE 0.04, p < 0.001)

• No effect on lung cancer risk (ATE coeff -0.03, SE 0.03, p = 0.4)

• This observational study of 634 consecutive IPF patients concluded that antifibrotic drugs significantly impact hospitalizations, acute exacerbations, and IPF survival

Meta-analysis of Antifibrotic Treatment (2022)

• Intervention: Nintedanib and pirfenidone (antifibrotic medications)

• Efficacy outcomes:

• Decreased risk of all-cause mortality with a pooled RR of 0.55 (95% CI, 0.45-0.66)

• Reduced risk of acute exacerbation with a pooled RR of 0.63 (95% CI, 0.53-0.76)

• This comprehensive meta-analysis included 12,956 patients across 26 studies

Admilparant Phase 2 Study (2024)

• Intervention: Admilparant (BMS-986278), an oral lysophosphatidic acid receptor 1 antagonist

• Efficacy outcomes:

• Rates of change in percentage of predicted FVC over 26 weeks for IPF were -2.7% (placebo), -2.8% (30 mg), and -1.2% (60 mg)

• Treatment differences between 60-mg admilparant and placebo were 1.4% (95% CI, -0.1 to 3.0) for IPF

• Treatment effect was observed with or without background antifibrotics

• Safety outcomes: 60-mg admilparant was safe and well tolerated
• This randomized, double-blind, placebo-controlled trial concluded that 60-mg admilparant slowed lung function decline

NICEFIT Registry (2022)

• Intervention: Antifibrotics nintedanib or pirfenidone
• Efficacy outcomes: The 2-year assessment revealed overall preserved lung functionality in the treated patients, with insignificant changes from baseline for percent predicted forced vital capacity (±1.7%)
• This Taiwan-based prospective, observational registry collected data on 101 patients with IPF over 2 years

Combination Therapy Study (2022)

• Intervention: Losartan in combination with pirfenidone
• Efficacy outcomes: The combined administration provided more potent protection against IPF than single therapy, boosting anti-inflammatory, anti-fibrotic, and anti-oxidant effects
• This study tested the effects on bleomycin-induced lung fibrosis in rats

Pirfenidone in CLAD Patients (2021)

• Intervention: Pirfenidone
• Safety outcomes: Good safety profile similar to that reported for IPF patients, with significant side effects occurring in only one case out of nine CLAD patients
• Efficacy outcomes: Potential for stabilizing decline in respiratory function, with FEV1 decline reducing from -44.5±40.7 mL/month before therapy to -12.8±34.3 mL/month in the following 6 months