Characteristics Total Total Cohort 1 Cohort 1 Cohort 2 Cohort 2 P value§
N 7069 7069 3233 3233 3836 3836
Age (years) 12.1 0.67 12.70 0.34 11.66 0.48 <0.001
Male sex 3618 51.2% 1669 51.6% 1949 50.8% 0.51
BMI (kg/m2) 20.5 4.14 20.57 4.23 20.37 4.06 0.08
Parental education <0.001
High school or below 4110 58.1% 2085 64.5% 2025 52.8%
College or university 2520 35.7% 1026 31.7% 1494 39.0%
Postgraduate 439 6.21% 122 3.77% 317 8.26%
Family income (NT$) <0.001
<600,000 3926 55.5% 2021 62.5% 1905 49.7%
600,001–1,000,000 2143 30.3% 848 26.2% 1295 33.8%
>1,000,001 1000 14.2% 364 11.3% 636 16.6%
Physician-diagnosed asthma 611 8.64% 253 7.83% 358 9.33% 0.03
FEV1/FVC (%) 91.5 6.07 90.85 5.31 92.11 6.69 <0.001