End-points used in clinical trials to assess disease progression in idiopathic pulmonary fibrosis

Lung function
  • Rate of decline in FVC (mL·year−1)

  • Absolute or relative changes in FVC (mL or % predicted)

  • Absolute or relative changes in DLCO % predicted

  • Categorical declines in FVC or DLCO (mL or % predicted)

Exercise capacity
  • Absolute change in 6-min walk test distance

  • Categorical decline in 6-min walk test distance

  • Change in oxygen saturation nadir during 6-min walk test

Patient-reported outcomes
  • Open question(s) on symptoms

  • St George's Respiratory Questionnaire (SGRQ)

  • University of California San Diego Shortness of Breath Questionnaire (UCSD-SOBQ)

  • Cough and Sputum Assessment Questionnaire (CASA-Q)

  • EuroQol 5-Dimensional Quality of Life Questionnaire (EQ-5D)

  • Short-Form Health Survey (SF-36)

Acute worsenings
  • Acute exacerbations

  • Respiratory hospitalisations

  • All-cause hospitalisations

  • All-cause mortality

  • Death due to respiratory cause

  • Progression-free survival

Radiological markers
  • Quantitative fibrosis scores based on HRCT

Serum biomarkers
  • Krebs von den Lungen-6 protein (KL-6)

  • Surfactant proteins D and A

  • Neoepitopes (biomarkers of extracellular matrix turnover)

FVC: forced vital capacity; DLCO: diffusing capacity of the lung for carbon monoxide; HRCT: high-resolution computed tomography.