The association between asthma and anxiety in elementary school students in Japan.

Background Studies on the association between asthma and anxiety in Asian children are limited. Therefore, we aimed to evaluate the association between asthma and anxiety among Japanese elementary school students. Methods A cross-sectional study of the association between asthma and anxiety in primary school children in Matsuyama City was conducted in 2014. The questionnaires included inquiries on asthma, anxiety, and other demographic variables. After excluding missing values, 17 752 (51.5% male) children were included in the analysis. The presence of asthma (yes/no) was answered by guardians. A score of four or more on the emotional symptom subscale of the strengths and difficulties questionnaire was considered as having anxiety. A Rohrer index score of 145 or more was considered as overweight. We estimated the prevalence ratio (PR) of having anxiety in relation to the presence of asthma based on the Poisson regression model. Results The multivariate PR (95% confidence interval) of having anxiety in asthmatic boys compared with non-asthmatic boys was 1.56 (1.21-1.99). The association was more evident in older than younger boys, where PR = 1.32 (0.93-1.88) for younger versus 1.87(1.32-2.64) for older boys (Pfor interaction = .08); and in non-overweight boys than overweight, where PR = 1.64 (1.27-2.13) and 0.94 (0.41-2.19) (Pfor interaction = .22), respectively. Similar associations were not found for girls. Conclusion Asthma was significantly associated with anxiety in boys, particularly in older boys.