Skip to main content
. 2015 Sep 8;9(Suppl 1):41–49. doi: 10.4137/CCRPM.S23288

Table 1.

Disease severity staging of IPF according to the Japanese Respiratory Society Guidelines.

STAGE PaO2 AT REST SpO2 DURING SIX-MINUTE WALK TEST
I ≥80 Torr –
II ≥70 Torr and <80 Torr If <90%, classified as stage III
III ≥60 Torr and <70 Torr If <90%, classified as stage IV
IV <60 Torr –

Abbreviations: IPF, idiopathic pulmonary fibrosis; PaO2, partial pressure arterial oxygen; SpO2, oxygen saturation as measured using pulse oximeter.