Table 1.

Dyspnea measurement used in GOLD guidelines and the current study

GOLD classification	mMRC wordinga	Current study wording	Analysis group
Less symptoms	0: I only get breathless with strenuous exercise	I only get breathless after strenuous exercise I get breathless after moderate exercise	Lower dyspnea
	1: I get short of breath when hurrying on level ground or walking up a slight hill	I get breathless when hurrying on level ground or walking up a slight incline
More symptoms	2: On level ground, I walk slower than people of the same age because of breathlessness, or have to stop for breath when walking at my own pace	I walk slower than most people my age due to my breathing I sometimes have to stop for breath even when walking on level ground at my own pace	Higher dyspnea
	3: I stop for breath after walking about 100 yards or after a few minutes on level ground 4: I am too breathless to leave the house or I am breathless when dressing	I stop for breath every few minutes while walking, even on level ground I am too breathless to leave the house
		None of the above	Excluded

Note:

^amMRC scale is used with the permission of the Medical Research Council.

Abbreviations: GOLD, Global Initiative for Chronic Obstructive Lung Disease; mMRC, modified Medical Research Council.