| Study | FITSA | KORA Age | KORA F3 | KORA F4 | NFBC 1966 | TwinFat | TwinsUK |
| Subjects | 386 | 905 | 875 | 1291 | 4984 | 219 | 3935 |
| Females n (%) | 386 (100) | 451 (49.8) | 458 (52.3) | 691 (53.5) | 2594 (52.0) | 101 (46.1) | 3687 (93.7) |
| Age years | 68.45±3.38 | 75.67±6.34 | 44.45±8.93 | 51.62±5.73 | 31±0.2 | 27.60±1.98 | 51.17±13.12 |
| FEV1 L | 2.20±0.49 | 2.49±0.72 | 3.56±0.82 | 3.34±0.82 | 3.95±0.79 | 4.03±0.84 | 2.74±0.66 |
| FVC L | 2.82±0.59 | 3.36±0.93 | 4.3±1.02 | 4.30±1.01 | 4.72±0.99 | 4.74±1.12# | 3.41±0.73 |
| FEV1/FVC % | 78.19±8.29 | 74.32±8.42 | 83.09±7.08 | 77.65±6.16 | 84.11±6.43 | 84.98±6.07# | 80.42±8.47 |
| FEV1 z-score | 0.19±1.34 | 0.35±1.17 | 0.17±1.06 | 0.21±1.16 | 0.21±1.01 | −0.03±1.09 | −0.09±1.13 |
| FVC z-score | 0.13±1.19 | 0.47±1.01 | −0.06±0.98 | 0.33±0.97 | 0.11±0.95 | −0.29±1.04# | −0.09±0.98 |
| FEV1/FVC z-score | −0.54±1.13 | −0.26±0.97 | 0.42±1.13 | −0.28±0.89 | 0.15±1.13 | 0.20±0.96# | −0.02±1.12 |
| Smoking status never/former/current | 333/31/21 | 510/351/44 | 377/260/238 | 496/496/299 | 2479/592/1913 | 110/54/55 | 2760/743/432 |
Data are presented as n or mean±sd, unless otherwise stated. FITSA: Finnish Twin Study on Ageing; KORA: Cooperative Health Research in the Region Augsburg; NFBC: Northern Finland Birth Cohort Study; FEV1: forced expiratory volume in 1 s; FVC: forced vital capacity. #: n=124.