Chronic cough (>8 weeks in duration) affects 5-12% of the global population, and is associated with considerable health status impairment and comorbidities. Currently, there are validated severity and impact outcome measures whilst objective measures with cough frequency monitoring is not available in routine clinical practice. Unlike other chronic respiratory diseases, namely asthma, there are no validated dedicated tools to assess the control of cough as a disease.

This study aims to develop a validated patient-focused tool to assess the control of cough, which may be useful to evaluate the benefit and value of treatments in both clinical and research settings.

This study will involve 3 phases:

• Phase 1: Literature review. Review of currently available validated tools to assess control in respiratory diseases.
• Phase 2: Development of Cough Control Questionnaire (CCQ). Patient focus groups will aid development of a conceptual framework of cough control and ensure content validity through qualitative research methods including thematic analysis. Expert panel review of cough control framework will also be undertaken. CCQ item development will be grounded in patient focus groups and expert review findings, and reviewed through cognitive debrief with patients.
• Phase 3: Validation of CCQ. Prospective consecutive patients with chronic cough will complete CCQ, cough severity assessments and health status assessments. Patients will be invited to undergo objective cough frequency monitoring and cough challenge testing.

Inclusion Criteria:

• Adult patients aged 18 and over with acute and chronic cough (including refractory chronic cough and unexplained chronic cough) and able to read and write in English. A smaller number (n =20) of healthy volunteers will also be included with no evidence of significant respiratory disease.

Exclusion Criteria:

• Current smokers (or smoking within the last 12 months), respiratory tract infection within the last 4 weeks, use of angiotensin converting enzyme inhibitors (ACEi), and pregnancy

Consecutive patients will be recruited from tertiary chronic cough clinics.

As the project progresses, other sites may be added. Only pseudonymised data would be sent to other researchers, for the purpose of statistical analysis and results.