Reliability and validity of a Dutch version of the Leicester Cough Questionnaire

Background Chronic cough is a common condition with a significant impact on quality of life. Currently, no health status measure specific for chronic cough exists in the Netherlands. Thus we developed a Dutch version of the Leicester Cough Questionnaire (LCQ) and tested its scaling and clinical properties. Methods The LCQ was adapted for Dutch conditions following a forward-backward translation procedure. All patients referred to our cough clinic between May 2004 and February 2005 completed five questionnaires, the LCQ, the modified Borg score for cough, the Short-Form 36 (SF-36), the Hospital Anxiety and Depression Scale (HADS) and the Global Rating of Change (GRC) upon presentation, after two weeks and after 6 months. Concurrent validation, internal consistency, repeatability and responsiveness were determined. Results For the concurrent validation the correlation coefficients (n = 152 patients) between the LCQ and the other outcome measures varied between 0.22 and 0.61. The internal consistency of the LCQ (n = 58) was high for each of the domains with a Crohnbach's alpha coefficient between 0.77 and 0.91. The two week repeatability of the LCQ in patients with no change in cough (n = 48) was high with intraclass correlation coefficients varying between 0.86 and 0.93. Patients who reported an improvement in cough (n = 140) after 6 months demonstrated significant improvement on each of the domains of the LCQ. Conclusion The Dutch version of the LCQ is a valid and reliable questionnaire to measure (changes of) health status in patients with chronic cough.