Background: Primary intervention - reducing second hand smoking (SHS), indoor dampness, and increased intake of omega-3-fatty acids - for allergic diseases such as asthma, rhinoconjunctivitis, and eczema/dermatitis in children was started in Trondheim in 2002. To our knowledge, no validated or reliable questionnaires for the study age groups were available.
Aims: To test the reliability of a revised questionnaire for studying atopic disease in children two to six years old in Trondheim.
Methods: Seventy-seven families were invited to fill in a questionnaire adapted from the ISAAC protocol which was made appropriate for the age group studied. Completed questionnaires and information from medical records were compared, and the agreement was analysed by Kappa statistics and proportional agreement.
Results: Agreement was excellent for questions reporting current information such as doctor-diagnosed asthma (kappa=0.88), whether or not the child had had an allergy test (kappa=0.82), and use of antibiotics (kappa=0.81). The agreement was good for questions concerning doctor or hospital treatment for asthma (kappa=0.59), medication for asthma (kappa=0.58), symptoms of eczema (kappa=0.56), medication for allergic disease (kappa=0.45), and past infections (kappa=0.53).
Conclusion: Questions on asthma diagnosis, allergy testing, and use of antibiotics were reliable. Questions on medical treatment for eczema, allergic rhinoconjunctivitis and infections were less reliable, representing a potential source of information bias and possible misclassification.