Table 1– Change in 6-min walk test (6MWT) performance on ambulatory oxygen

	6MWT at baseline	6MWT on oxygen^#	p-value
In all ILD patients^¶
Distance m	255.1±16.8	286.0±14.9	<0.00001
S_a,O₂ end test %	76.3±1.1	84.7±1.1	<0.00001
Borg scale end test⁺	4.75 (4–5)	3.75 (3–4.3)	<0.00001
Heart rate end test	120.4±2.0	115.9±2.3	0.03
Heart rate recovery time s	218.5±19.9	145.5±10.4	<0.00001
Borg score recovery time s	185.3±21.2	133.7±12.8	0.0002
S_a,O₂ recovery time s	183.6±20.2	102.7±8.5	<0.00001
In patients who completed both 6MWTs without stops^§
Distance m	318.9±15.4	332.3±15.1	0.002
S_a,O₂ end test %	78.2±1.2	86.7±1.1	<0.00001
Borg scale end test⁺	4.0 (3–5)	3.5 (2.5–4)	<0.00001
Heart rate end test	118.6±2.6	112.5±3.1	0.04
Heart rate recovery time s	210.4±27.6	132.3±11.9	0.001
Borg score recovery time s	175.1±29.6	116.0±16.1	0.001
S_a,O₂ recovery time s	162.2±24.2	83.8±8.3	0.0005
In patients who stopped at least once during the baseline 6MWT^ƒ
Distance m	144.2±19.2	205.6±21.2	0.0001
S_a,O₂ end test %	73±2.0	81.3±2.0	<0.00001
Borg scale end test⁺	5 (4–6.7)	5 (3.3–6.0)	0.02
Heart rate end test	123.5±3.1	121.9±3.2	ns
Heart rate recovery time s	231.9±27.2	167.8±18.5	0.0007
Borg score recovery time s	203.2±27.4	164.5±19.6	0.07
S_a,O₂ recovery time s	220.6±35.3	135.7±15.8	0.004
In fibrotic IIP patients^##
Distance m	272.3±19.8	304.7±17.8	0.0001
S_a,O₂ end test %	75.6±1.1	83.4±1.3	<0.00001
Borg scale end test⁺	4.25 (3–5)	3.25±(2.5–4)	<0.00001
Heart rate end test	119.6±2.5	116.6±3.0	ns
Heart rate recovery time s	214.3±25.9	138.1±12.4	0.0003
Borg score recovery time s	167.1±28.2	120.7±15.5	0.008
S_a,O₂ recovery time s	177.4±24.2	104.0±10.5	0.0007

All values are expressed as mean±se unless stated otherwise. ILD: interstitial lung disease; S_a,O₂: arterial oxygen saturation; IIP: idiopathic fibrotic interstitial pneumonia. ^#: additional or increased; ^¶: n=52; ⁺: median (95% CI); ^§: n=33; ^ƒ: n=19; ^##: n=34.