Measurement of cough

Cough is one of the most common symptoms encountered by clinicians particularly when it is persistent. Assessment of cough is essential for determining treatment outcomes, testing new therapies and for study of pathophysiology and mechanisms. There are new tools for measuring different aspects of cough. Apart from the patient's subjective assessment of cough severity using clinical scores, the impact of cough on quality of life can be measured. Direct measurement of cough counts is now possible by using portable devices, but how the counts relate to severity is unclear. A measure of cough intensity is required. Cough reflex measured by response to inhaling citric acid or capsaicin provides a measure of cough sensitivity that may be related to cough severity. In many intervention studies of cough, the response has usually been measured in terms of physician assessment of cough and its changes in cough reflex. How the information obtained between these different measurements interrelate needs to be determined.