TABLE 1

Clinical tools for measurement of cough

Variable	Tool	Adaptable to routine practice?	References
Cough symptoms
Subjective cough severity	Visual analogue scale	Yes	[6]
Cough-related quality of life	Leicester cough questionnaire, cough-specific quality of life questionnaire	Yes	[6]
Objective description of coughing
Temporal cough patterns^#	Ambulatory cough monitoring	Yes	[6, 7]
Force/intensity of coughs	Airflow measurements, electromyography, oesophageal pressure monitoring	Possibly	[7]
Sensitivity to inhaled irritants	Inhalational cough challenge	Possibly	[6]
Cough mechanism
Airway inflammation	BAL sample analysis, induced sputum cell counts, exhaled nitric oxide fraction, exhaled volatile organic compounds	Yes	[1, 9]
Neuronal mechanisms	Animal models, human surgical and autopsy specimens	No	[6]
Central pathways	Functional magnetic resonance imaging	Possibly	[10]
Genetic predisposition	Genotyping for single nucleotide polymorphisms of potential genes including TRPV1	Possibly	[8, 10]

BAL: bronchoalveolar lavage. ^#: daily cough frequency, diurnal cough pattern and degree of clustering of coughs into bouts.