Background: The aim of this study was to assess the effectiveness of an asthma prevalence video questionnaire (involving the audiovisual presentation of clinical asthma), a standard written questionnaire (based on the IUATLD Bronchial Symptoms Questionnaire) and a new written questionnaire (designed for an international study of asthma and allergies in childhood [ISAAC]) in predicting bronchial hyper-responsiveness (BHR) (PD20 < or = 7.8 mumol methacholine).
Methods: The IUATLD and video questionnaires were administered to 193 schoolchildren (13-16 years). The ISAAC questionnaire was administered to 87 of these children. All children subsequently underwent bronchial challenge to methacholine.
Results: The sensitivity and specificity for predicting BHR were similar for individual questions from the IUATLD and video questionnaires. The video questions with the highest Youden's index related to moderate wheezing at rest (0.46), severe wheezing at rest (0.38), and nocturnal wheezing (0.37). The ISAAC questionnaire was similar in effectiveness to the IUATLD questionnaire in predicting BHR.
Conclusions: The video questionnaire is a valid method of assessing the prevalence of BHR, and may be particularly useful when comparing populations with differing languages and cultures. Some video questions appeared more effective than others in relation to predicting BHR. A new written questionnaire (ISAAC) designed for a large international asthma prevalence study in children also is an effective method for measuring the prevalence of BHR.