Impact of Gender on the Characteristics of Patients with Idiopathic Pulmonary Fibrosis Included in the RaDiCo-ILD Cohort

Background: There is growing evidence of gender-specific phenotypic differences among patients with idiopathic pulmonary fibrosis (IPF), which may affect patient outcomes. Objectives: We present the characteristics of patients with IPF at inclusion in the French Rare Disease Cohort - Interstitial Lung Disease (RaDiCo-ILD) with the aim of characterizing gender-specific phenotypic differences. Methods: Patients with IPF who were enrolled in the national, multicentre RaDiCo-ILD cohort were included. Demographic characteristics, comorbidities, health-related quality of life (HRQoL) scores, pulmonary function, chest imaging, and IPF treatment were collected at inclusion and described by gender. Results: The cohort included 724 patients with IPF (54% of RaDiCo-ILD cohort), of whom 82.9% were male. The proportion of male and female patients with a prior history of smoking was 75.0% and 26.8%, respectively. Emphysema was present in 17.0% (95% confidence interval [CI]: 10.0, 24.0) of men and 5.4% (95% CI: 1.2, 9.6) of women. At inclusion, females had poorer HRQoL than males based on St. George's Respiratory Questionnaire scores (48.5 [95% CI: 43.9, 53.0] and 41.5 [39.4, 43.6], respectively). The mean forced vital capacity per cent predicted was 77.7% (95% CI: 76.2, 79.3) and 87.4% (83.4, 91.4) for males and females, respectively. Honeycombing on high-resolution computed tomography (HRCT) was present in 70.8% (95% CI: 61.0, 80.6) of males and 45.8% (95% CI: 35.1, 56.5) of females. Conclusions: This analysis of patients with IPF at inclusion in the RaDiCo-ILD cohort provides evidence that comorbid emphysema, lung volume reduction, and honeycombing on HRCT are more common characteristics of males than females.