What do GAP stages predict in IPF?

GAP Stage I (0-3): 1-year mortality ~6%; Stage II (4-5): 1-year mortality ~16%; Stage III (6-8): 1-year mortality ~39%. GAP staging guides transplant referral timing and antifibrotic therapy discussions.

What inputs does the GAP index require?

GAP requires: sex (female 0, male 1 point), age (60-65 = 1, >65 = 2 points), FVC %predicted (<75% = 1, <50% = 2 points), and DLCO %predicted (<55% = 1, <36% = 2, unmeasured = 3 points).

GAP Score — Idiopathic Pulmonary Fibrosis Prognosis

Calculate the Gender-Age-Physiology (GAP) index for idiopathic pulmonary fibrosis to estimate 1, 2, and 3-year mortality probability based on sex, age, FVC, and DLCO.

Use the full interactive calculator below, or

GAP Score — Idiopathic Pulmonary Fibrosis Prognosis

Frequently Asked Questions

What do GAP stages predict in IPF?

What inputs does the GAP index require?