Comparison of the diagnostic criteria for progressive pulmonary fibrosis (PPF) in the ATS/ERS 2022 idiopathic pulmonary fibrosis and PPF guideline update and the INBUILD progressive fibrosing interstitial lung disease (PFILD) randomised control trial inclusion criteria
| ERS/ATS PPF criteria [3] (any 2 criteria) | INBUILD trial PFILD criteria [8] | |
| Forced vital capacity | Absolute decline ≥5% | Relative decline >10% OR 5–10% and any of the below criteria |
| Symptoms | Worsened respiratory symptoms | Worsened respiratory symptoms |
| DLCO | Absolute decline ≥10% | Not included |
| Radiology | Worsened fibrosis on HRCT | Worsened fibrosis on HRCT |
| Time-period decline/investigations must be within | 12 months | 24 months |
ATS: American Thoracic Society; ERS: European Respiratory Society; DLCO: diffusing capacity of the lung for carbon monoxide; HRCT: high-resolution computed tomography.