Chronic Cough Patient Perspective: questionnaire validation and symptom impact

Chronic cough (CC) is underevaluated and underreported. The introduction of a tool that is easy to complete, score and interpret and with the psychometric properties requested for use in individual patients could improve clinical practice.

This cross-sectional study aimed to validate the Chronic Cough Patient Perspective (CCPP) for assessing CC in daily practice.

A provisional CCPP was created by iteratively reducing the Chronic Cough Impact Questionnaire (CCIQ). Its psychometric properties were tested in CC patients at baseline (visit 1) and after 1 month (visit 2).

The reduction process yielded an 8-item provisional version, subsequently validated in 150 patients (36.33% males, mean age 50±16.9 years). Exploratory factor analysis revealed a one-dimensional structure, with one item being deleted as it did not align with the extracted dimension. The 7-item version of the CCPP showed a strong correlation with the CCIQ (r=0.902 at visit 1, r=0.932 at visit 2) and internal consistency (Cronbach's alpha values: 0.85 at visit 1, 0.93 at visit 2); discriminant and convergent validity were satisfactory. The reliability, assessed in 21 patients with no change in CC (Global Rating Scale=0), was high (concordance correlation coefficient=0.815; interclass coefficient=0.823). A score ≤5 indicates optimal health-related quality of life (HRQoL) attainment, with a minimum important difference of 3. The mean CCPP score was 20.5±6.24 at enrolment, and only 37.33% of the participants achieved an optimal HRQoL at visit 2.

The CCPP exhibited good psychometric properties suitable for clinical use, providing a valid, reliable and standardised assessment of CC's impact on HRQoL.