Purpose: To investigate changes in the prevalence of adult asthma and allergic rhinitis from 2006 to 2011 in Kamishihoro, a town in Hokkaido, Japan.
Methods: The Japanese edition of the European Community Respiratory Health Survey questionnaire was completed by 1472 residents aged from 20 to 81 years old. (718 men, 749 women). The age and gender distribution of respondents matched that of respondents in 2006.
Results: Response rates were 98.1% in 2011 and 95.8% in 2006. Wheezing in the last 12 months was reported by 10.7% of men and 8.3% of women in 2011, compared to 12.9% and 9.8%, respectively, in 2006. The questions "Have you ever had asthma?" followed by "Was this confirmed by a doctor?" both received positive answers from 7.9% of men and 7.5% of women in 2011, compared to 5.7% and 6.3%, respectively, in 2006. The rate of current smoking was 34.8% in men and 14.7% in women in 2011, compared to 42.8% and 17.2%, respectively, in 2006. A "Yes" answer to the questionnaire item, "Do you have any nasal allergies, including hay fever?" (defining allergic rhinitis) was given by 23.2% of men and 25.4% of women in 2011, compared to 17.6% and 23.0%, respectively, in 2006. The prevalence of allergic rhinitis was increased, particularly among younger respondents.
Conclusion: Rates of current asthma and allergic rhinitis increased, whereas the rate of wheezing in the past 12 months decreased from 2006 to 2011. Optimal treatment of asthma might be related to these trends.