Spirometry in 10,195 lifelong nonsmokers
| Variable | Total | Males | Females | Males versus females p-value |
| Subjects n | 10195 | 3458 | 6737 | |
| Normal lung function | 8038 (78.84) | 2781 (80.42) | 5257 (78.03) | <0.01 |
| Airflow limitation | 1262 (12.38) | 434 (12.55) | 828 (12.29) | 0.73 |
| Mild# | 554 (5.43) | 201 (5.81) | 353 (5.24) | 0.25 |
| Moderate¶ | 422 (4.14) | 125 (3.61) | 297 (4.41) | 0.06 |
| Severe+ | 286 (2.81) | 108 (3.12) | 178 (2.64) | 0.18 |
| Restriction | 895 (8.78) | 243 (7.03) | 652 (9.68) | <0.001 |
Data presented as n (%), unless otherwise stated. #: classified as forced expiratory volume in one second (FEV1) ≥70% predicted; ¶: FEV1 50–69% pred; +: FEV1 <50% pred.