Exercise-induced asthma is associated with impaired quality of life amon children with asthma in Japan

Background: Asthma is the most common chronic diseases in school-aged children in Japan. It is important to consider health-related quality of life (QoL) among children with chronic diseases when treatment decisions are made. Methods: A school-based survey was conducted in randomly selected public schools in Tokyo by using a KINDL® questionnaire for evaluating QoL and the international study of asthma and allergy on childhood (ISAAC) questionnaire, which is designed for comparing the asthma prevalence in various countries, from May to June in 2005. We recruited approximately 10% of the total children 6-7-years-old and 13-14-years-old living in Tokyo for sampling. Results: Response rate of this questionnaire was 86% (22,645 children) in the 6-7-year-old group and 64% (12,879 children) in the 13-14-year-old group. Comparing asthmatics with non-asthmatics in the same age, QoL of children with asthma was significantly impaired. The severity of QoL of children with asthma was significantly impaired. QoL of children with exercise-induced asthma (EIA) were more significantly impaired than ones without EIA and showed lower scores in the categories of physical functioning, emotional and school activities than those without EIA. Of note, QoL was more impaired in the EIA-positive group among severe asthmatics, suggesting that QoL of children with even severe asthma could be improved when EIA is appropriately controlled. Conclusions: Existence of EIA among asthmatic children most strongly impairs their QoL. We should be more cautious about the management of EIA.