A parent-completed respiratory questionnaire for one-year olds: repeatability

Background and aims: There are few standardised questionnaires for the assessment of respiratory symptoms in preschool children. We have developed and tested the short-term repeatability of a postal questionnaire on respiratory symptoms for one-year olds. Methods: A newly developed postal questionnaire for the assessment of wheeze and other respiratory symptoms was sent to parents of a population-based random sample of 4300 children aged 12 to 24 months. After an interval of 3 months, a random sample of 800 respondents received the questionnaire a second time. The responses were compared using Cohen’s kappa (κ) to assess agreement corrected for chance. Results: The first questionnaire was returned by 3194 (74%) families, the second one by 460/800 (58%). Repeatability was excellent (κ 0.80-0.96) for questions on household characteristics, environmental exposures and family history, good (κ 0.61-0.80) for questions on prevalence, severity and treatment of wheeze, and moderate (κ 0.39-0.66) for chronic cough and upper respiratory symptoms. Conclusions: This short postal questionnaire designed for use in population-based studies has excellent repeatability for family and household characteristics and good repeatability for questions on wheeze. Short-term changes in symptom status might be responsible for variable answers on recent chronic cough and upper respiratory symptoms. Overall, the questionnaire is a valuable instrument for community-based research on respiratory symptoms in one to two-year old children.