to join the Niigata Asthma Treatment Study Group The study was performed with the approval of the Ethics Committee at the School of Medicine of Nii-gata University (approval #1090) in Niigata Prefec-ture, Japan, in accordance with the Ethical Principlesfor Medical Research Involving Human Subjects(Declaration of Helsinki). Written informed consent to participate was obtained from all patients. The questionnaire was written in Japanese. The question-naire survey was administered between September and October 2010. The subjects comprised patients
aged 16 or more years with bronchial asthma who
regularly visited the participating institutions for
asthma management (typically once or twice per
month). The recruited patients were asked to com-
plete the questionnaire without assistance and were
thus expected to understand the technical terms such
as “attack” used in the questionnaire.