GAP Index for Idiopathic Pulmonary Fibrosis (IPF) Mortality
GAP Index for IPF Calculator
Gender
Age
FVC (% Predicted)
DLCO (% Predicted)
GAP Index:
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Awaiting input
Select all criteria to compute the score.
Provides 1, 2, and 3-year mortality estimates for IPF patients.
Why Use
Simple, externally validated, scoring system using readily available baseline parameters.
When to Use
1, 2, and 3-year prognostication for IPF patients needing lung transplantation.
Formula
Addition of assigned points. The GAP Score stands for the “Gender, Age, and Physiology score.” Gender and Age each have one associated criterion. Physiology has two associated criteria (FVC and DLCO).
Pearls / Pitfalls
The GAP index is more sensitive, but less specific, than the the du Bois Score for predicting mortality. The external validation concludes that the GAP index correlates well with 1-year mortality but NOT 3-year mortality.
Advice
Higher GAP stages and scores correspond to a greater need for transplantation and other treatments.
More Information
GAP staging for IPF: Mortality Points Stage 1-year 2-year* 3-year* 0-3 I 5.6% 10.9% 16.3% 4-5 II 16.2% 29.9% 42.1% 6-8 III 39.2% 62.1% 76.8% *The GAP index is more sensitive, but less specific, than the the du Bois Score for predicting mortality.