The psychometric properties of the Leicester Cough Questionnaire and Respiratory Symptoms in CF tool in cystic fibrosis: A preliminary study

Background There are few tools to quantify the impact of cough in cystic fibrosis (CF). The psychometric properties of the Leicester Cough Questionnaire (LCQ) and Respiratory Symptoms in CF (ReS-CF) tool were investigated in adults with CF. Methods Validity and reliability were assessed in clinically stable participants who completed the questionnaires twice, along with the Cystic Fibrosis Questionnaire – Revised (CFQ-R). Responsiveness was assessed by change in questionnaires following treatment for an acute respiratory exacerbation. Results Correlations between the LCQ and CFQ-R respiratory domain were moderate (n = 59, r_s = 0.78, p < 0.001). Correlations between ReS-CF and CFQ-R respiratory domain were fair (r_s = − 0.50, p < 0.001). The LCQ total score was repeatable (ICC 0.92, 95%CI 0.87–0.96, n = 50). In those reporting improvement in symptoms following treatment (n = 36), LCQ total score had a mean change of 4.6 (SD 3.7) and effect size of 1.2. Conclusions The LCQ and ReS-CF appear to be valid, reliable and responsive in CF. Trial Registration: www.anzctr.org.au: ACTRN12615000262505