Validation of the Chinese translated version of ISAAC core questions for atopic eczema

Background The International Study of Asthma and Allergies in Childhood (ISAAC) was designed to allow international comparison of epidemiological data on atopic conditions in childhood. In so doing, further aetiological information would be obtained that in turn would provide a framework for future studies. The global ISAAC results on the prevalence of atopic dermatitis indicated a 60-fold variation recorded in different countries. Such a degree of difference may be partially due to the translated questionnaires that were not validated in all of the involved countries. Objective To validate the Chinese version of the ISAAC core questions for atopic eczema. Methods One thousand nine hundred and twenty children aged between 3 and 5 were randomly recruited from 13 kindergartens in Hong Kong. Using a dermatologist's clinical examination as the gold standard, we validated the Chinese version of the ISAAC core questions for atopic eczema. The Youden's Indexes obtained in our study were compared with those obtained in the United Kingdom's validation study. Results The Youden's Indexes obtained in our study were significantly tower than those from the United Kingdom. The low scores were likely to be due to a reduction in the sensitivity of the Chinese questionnaire, which ranged from 23.5% to 70.6%. Conclusion Our findings indicate that the translated questionnaire is less effective than the English version in assessing the prevalence of atopic eczema. The indication of a low prevalence of atopic eczema among the Chinese population reported in previous studies was at least partially due to problems with the translated questionnaire.