Validation of a pediatric cough questionnaire.

We conducted a study to determine if a five-item pediatric cough questionnaire (PCQ) is a valid and reliable means of measuring cough-specific quality of life in children. The five questions, which are answered by the child's parent or caregiver, cover cough frequency (Q1), sleep disturbance of the child (Q2), sleep disturbance of the parent (Q3), cough severity (Q4), and the degree of bothersomeness to the child (Q5). Each of the five items was scored on a 6-point Likert scale. The PCQ was administered three times. The first occurred when the parent telephoned to schedule an appointment for the child at a pediatric pulmonology outpatient clinic for a chief complaint of cough. The second PCQ was administered within 2 weeks of the first but before any treatment had been instituted so that test-retest reliability could be assessed. Each child was then diagnosed and treated in accordance with standard care practices. The third PCQ was administered 3 weeks after the second to determine if it would accurately reflect the parent's perception of how the child's cough had changed following treatment. Also, at the second and third encounters, parents were asked to provide their global assessment of whether their child's cough had improved, worsened, or stayed the same since the previous encounter. The parents of 120 children (70 boys and 50 girls; mean age: 6.8 yr) completed all three PCQs. Test-retest reliability was established (p < 0.001) for each of the five PCQ questions by Spearman correlation analysis (Q1: r = 0.5; Q2: r = 0.38; Q3: r = 0.42; Q4: r = 0.53; Q5: r = 0.5). Other statistical analyses confirmed the PCQ's internal consistency, discriminant validity, and convergent validity. Based on our findings, we conclude that the PCQ is a valid and reliable instrument with which to follow children with chronic cough longitudinally.