TABLE 4.

DOMAINS OF DYSPNEA MEASUREMENT

Domain	Definition	Examples*
Sensory–perceptual experience	Measures of what breathing feels like to the patient or research subject.	Single item ratings of intensity (e.g., Borg scale, VAS)
		Descriptors of specific sensations/clusters of related sensations
Affective distress	Measures of how distressing breathing feels. Focus can be either immediate (e.g. unpleasantness) or evaluative (e.g., judgments of meaning or consequences).	Single-item ratings of severity of distress or unpleasantness
		Multi-item scales of emotional responses such as anxiety
Symptom impact or burden	Measures of how dyspnea/breathlessness affects functional ability, employment (disability), quality of life, or health status.	Unidimensional rating of disability or activity limitation (e.g., MRC scale)
		Unidimensional or multidimensional ratings of functional ability
		Multidimensional scales of quality of life/health status

Definition of abbreviations: MRC = Medical Research Council; VAS = visual analog scale.

^*Specific measures cataloged in Table E1.