Study characteristics and prevalence of atopic diseases
Of the 47,015 children born in 2001 in the cohort, the data on the factors were available in 38,540; 36,798; 36,151; 35,275; 34,145; and 32,913 children at the ages of 5.5, 7, 8, 9, 10, and 11 years, respectively. The clinical characteristics of the study subjects were determined to be similar between the ages of 5.5 and 11 years and are presented in Table 1 and Tables S2–6. The prevalence of asthma was reported to be 8.6% at 5.5 years and showed a linear decrease to 5.4% at 11 years (Figure S1). Atopic dermatitis showed a similar trend: 7.8% at 5.5 years and 5.9% at 11 years. On the contrary, the prevalence of allergic rhinitis/conjunctivitis showed a linear increase, with 13% at 5.5 years and 24% at 11 years.