Fig. 4

Percentage of patients with IPF experiencing significant (∆FVC >10%) or marginal (10% ≥ ∆FVC>5%) improvement, stabilization (+5% ≥ ∆FVC>-5%), and marginal (−5% ≥ ∆FVC>-10%) or significant (∆FVC ≤ -10%) decline based on the rate of changes of FVC % of predicted (∆FVC) in the 6-months intervals during pirfenidone treatment