Background: We conducted and reported the first (1982; 55,388 subjects), and second (1992; 45,674 subjects), epidemiological surveys conducted on bronchial asthma in elementary students across 11 prefectures in western Japan. The 2 surveys were conducted in the same regions using the same methodology employing a modified Japanese version of the American Thoracic Society-Division of Lung Diseases (ATS-DLD) Epidemiology Questionnaire. We conducted the third survey in 2002, and compared the findings to those of previous studies.
Methods: In the third survey, 37,036 students attending the same schools as in previous surveys (in 11 prefectures) were given the questionnaire. A total of 35,582 responses (96.1%) were collected. An ATS-DLD Epidemiology Questionnaire was also used in this study, and the findings were compared to those of previous studies.
Results: 1. The prevalence of bronchial asthma (BA) in boys, girls, and all students was 3.8%, 2.5%, and 3.2%, respectively, for the first survey; 5.6%, 3.5%, and 4.6% for the second survey; and 8.1%, 4.9%, and 6.5% for the third survey. 2. A decline in the BA prevalence in older subjects which could be seen in the first survey was absent in the second and third surveys. There were no regional differences in the third survey. 3. The boys-to-girls ratio in the first, second, and third surveys was 1.5, 1.6, and 1.6, respectively. 4. BA was more prevalent among subjects with a past history of respiratory disease in infancy and those with a family history of allergic disease. 5. The prevalence of asthma symptoms and wheezing in the first, second, and third surveys was 7.1%, 9.8%, and 11.8%, respectively. 6. A comparison of the prevalence of other allergic diseases between the second and third surveys revealed a decrease in atopic dermatitis and an increase in allergic rhinitis, allergic conjunctivitis, and cedar pollinosis.
Conclusions: BA prevalence in the third survey increased 2.1 and 1.4 times respectively compared to the first survey and second survey, indicating an upward trend in all regions and age groups surveyed.