Patient demographics, pulmonary function indices and visual and computer-based scores of ILD and PPFE severity for IPF and FHP patients in the study
| Variable | IPF cohort | FHP cohort | p-value |
| Patients n | 414 | 98 | |
| Baseline age years, median (range) | 69 (32–95) | 64 (28–85) | 0.0001 |
| Male/female % | 24.2/75.8 | 62.2/37.8 | <0.0001 |
| Survival (alive/dead) % | 44.4/55.6 | 54.1/45.9 | 0.11 |
| Follow-up years, median (range) | 2.2 (0.0–9.0) | 2.7 (0.0–12.0) | 0.013 |
| Time between CT scans years, median (range) | 1.1 (0.5–3.0) | 1.1 (0.5–2.9) | 0.81 |
| Never-/ever-smokers % | 30.7/69.3 | 50.0/50.0 | 0.0005 |
| Antifibrotic (never/ever) % | 30.7/69.3 | ||
| Baseline FVC % predicted | 81.3±19.7 | 64.2±19.6 | <0.0001 |
| Baseline DLCO % predicted | 48.8±15.9 | 50.5±16.8 | 0.44 |
| Baseline emphysema (absent/present) % | 32.4/67.6 | 69.4/30.6 | <0.0001 |
| Baseline ILD extent % | 39.0±12.3 | 33.3±14.0 | 0.0003 |
| Δ-ILD %/year | 7.7±8.7 | 4.0±5.6 | <0.0001 |
| Baseline PPFE extent % | 2.0±2.4 | 1.9±2.3 | 0.74 |
| Δ-PPFE %/year | 0.8±2.0 | 0.8±2.4 | 0.93 |
| Clinically important baseline PPFE prevalence % | 29.5 | 26.5 | 0.65 |
| Progressive PPFE prevalence % | 21.5 | 25.5 | 0.47 |
| Δ-PPFE-adj in progressive PPFE patients %/year | 2.3±2.7 | 2.4±3.3 | 0.86 |
Pulmonary function indices, ILD extent and PPFE scores are described as mean±sd. Clinically important PPFE at baseline was defined as baseline PPFE extent >2.5%. Progressive PPFE was defined as Δ-PPFE >1.25%/year. ILD: interstitial lung disease; PPFE: pleuroparenchymal fibroelastosis; IPF: idiopathic pulmonary fibrosis; FHP: fibrotic hypersensitivity pneumonitis; CT: computed tomography; FVC: forced vital capacity; DLCO: diffusing capacity of the lung for carbon monoxide; Δ-ILD: annualised change in ILD extent between CT scans; Δ-PPFE: annualised change in computerised upper-zone PPFE between scans; Δ-PPFE-adj: Δ-PPFE above scan noise.