Estimated changes of forced vital capacity z-scores with birth cohort in the total population
| Males | Females | |||||||
| Birth cohort | n | Coefficient | 95% CI | p-value | n | Coefficient | 95% CI | p-value |
| 1894–1904 | 469 | - | - | - | 640 | - | - | - |
| 1905–1914 | 517 | 0.00 | (−0.12–0.12) | 0.990 | 720 | 0.13 | (0.02–0.24) | 0.020 |
| 1915–1924 | 674 | 0.14 | (0.03–0.26) | 0.010 | 790 | 0.28 | (0.18–0.39) | <0.001 |
| 1925–1934 | 1552 | 0.43 | (0.32–0.54) | <0.001 | 1580 | 0.54 | (0.43–0.66) | <0.001 |
| 1935–1944 | 2125 | 0.61 | (0.50–0.73) | <0.001 | 720 | 0.53 | (0.41–0.65) | <0.001 |
| 1945–1954 | 17 838 | 0.60 | (0.48–0.72) | <0.001 | 1095 | 0.50 | (0.36–0.64) | <0.001 |
| 1955–1964 | 7223 | 0.61 | (0.49–0.73) | <0.001 | 250 | 0.50 | (0.32–0.68) | <0.001 |
| 1965–1969 | 133 | 0.70 | (0.50–0.90) | <0.001 | 140 | 0.64 | (0.43–0.85) | <0.001 |
Linear mixed-effect models with random effects at the survey level, adjusted for smoking status, pack-years, education, lung diseases and respiratory symptoms. Birth cohort reference category = 1894–1904. Z-scores calculated according to Global Lung Function Initiative (GLI-2012) equations.