Project 458577

Chronic cough lasting >8 weeks is a common health problem with a global prevalence of 10%. In Canada, chronic cough has a prevalence of 16% and represents one of the most common reasons for referral to a respiratory specialist. Currently, there are no licensed treatments for this condition, but new therapy blocking the actions of ATP on airway nerves is under regulatory review. It is anticipated that this treatment will become available for prescription next year in Canada. Three other ATP blockers are also under investigation for chronic cough. The effectiveness of such therapies in clinical trials have been assessed using 24-hour objective cough frequency. Objective cough monitors are limited, however, in that they are not feasible for use in clinical practice due to expense ($2000 per use) and limited 24-hour recording. Alternative patient reported outcome (PRO) measures to assess the severity of cough and effectiveness of antitussive treatments are urgently needed. Most validated PRO questionnaires for cough assess the impact of cough symptoms on quality of life. A limitation of cough-specific quality of life measures is that they do not assess whether treatment improves severity of the cough symptom itself. This is important because some interventions, such as pregabalin, may reduce the aversiveness and thereby the impact of the cough without improving the underlying problem. Existing PRO measures that assess cough symptom severity have neither been tested for validity or responsiveness, nor made widely available. Therefore, we aim to develop and establish the measurement properties of the McMaster Cough Severity Questionnaire (MCSQ). Development of the MCSQ will provide an important instrument for use in health research and clinical practice to assess the severity of cough and effectiveness of interventions for patients with chronic cough.