Table 2.
Descriptive Statistics of Lung Function Outcomes in the Study Population and Restricted to Subjects with Complete Data on Confounders and Control Variables by Sex
| Lung Function Outcome | All Subjects in Study Population |
Restricted to Subjects with Complete Data on Confounders* and Control Variables† |
||
|---|---|---|---|---|
| Males | Females | Males | Females | |
| Adolescence (age, 15 yr) | n = 1,909 | n = 2,108 | n = 1,177 | n = 1,235 |
| FEV1, L | 3.86 (3.32–4.37) | 3.10 (2.71–3.46) | 3.86 (3.32–4.36) | 3.09 (2.69–3.46) |
| FVC, L | 4.23 (3.63–4.78) | 3.30 (2.88–3.69) | 4.20 (3.64–4.76) | 3.28 (2.90–3.68) |
| FEV1/FVC, % | 92.0 (87.2–96.7) | 94.4 (89.7–98.1) | 92.2 (87.5–96.8) | 94.2 (89.7–97.9) |
| FEF25–75%, L/s | 4.62 (3.85–5.45) | 4.04 (3.37–4.71) | 4.65 (3.88–5.46) | 3.99 (3.36–4.72) |
| Early adulthood (age, 24 yr) | n = 1,062 | n = 1,770 | n = 567 | n = 990 |
| FEV1, L | 4.61 (4.19–5.04) | 3.36 (3.06–3.66) | 4.61 (4.17–5.04) | 3.37 (3.10–3.66) |
| FVC, L | 5.50 (5.00–6.06) | 3.89 (3.53–4.24) | 5.49 (4.97–6.09) | 3.89 (3.55–4.25) |
| FEV1/FVC, % | 84.2 (80.3–87.7) | 86.9 (83.5–90.3) | 84.4 (80.6–87.9) | 86.7 (83.5–90.3) |
| FEF25–75%, L/s | 4.80 (4.04–5.55) | 3.82 (3.25–4.39) | 4.84 (4.06–5.59) | 3.84 (3.29–4.37) |
Definition of abbreviation: FEF25–75% = forced expiratory flow, midexpiratory phase.
Data are shown as median (interquartile range).
*
Confounders: parity; maternal history of asthma or allergy; maternal smoking during pregnancy; birth weight; ever doctor-diagnosed asthma by age 14 years; exposure to smoke from birth to age of 8 years; and smoking status.
†
Control variables: baseline lung function at 8 years old; and age and height at visit clinics in which outcomes, reported in the first column, were measured.