Development and Validation of Cough Hypersensitivity Assessment Test.

BACKGROUND

Cough hypersensitivity is an important clinical and pathophysiologic feature of chronic cough, which involves chemical, mechanical, and thermal stimuli and sensory dysfunction. Currently, there is a need for a comprehensive method to evaluate cough hypersensitivity.

OBJECTIVE

To develop and validate a questionnaire to assess the degree of cough hypersensitivity.

METHODS

The initial items of the Cough Hypersensitivity Assessment Test (CHAT) were made based on a literature review, experts' opinions, and clinical practice. Items were reduced after investigation involving patients with chronic cough. Dimensional allocation, internal reliability, test-retest reliability, construct validity, responsiveness, and cutoff value were determined in the final stage.

RESULTS

The final version of CHAT on a 5-point Likert scale (0-4) includes 18 items consisting of three dimensions: environmental triggers, daily life triggers, and tussive symptoms, with total score ranging from 0 to 72. There was significant difference in CHAT-18 scores between patients and healthy controls (P < .001). Cronbach α for CHAT was 0.832 and intraclass correlation coefficient for CHAT was 0.884. Construct validity was demonstrated with a multitrait-multimethod matrix. There was good responsiveness after treatment. The cutoff value of CHAT was 18 for cough hypersensitivity. There was a mild to moderate correlation between capsaicin cough sensitivity and tussive symptoms and the total score of CHAT.

CONCLUSIONS

The CHAT comprehensively covers a range of cough triggers and shows robust internal reliability, test-retest reliability, construct validity, and responsiveness. This may be useful for measuring cough hypersensitivity.