Educational level | |||
High | Intermediate | Low | |
Basic model+ | |||
Baseline FEV1 mL | Ref | -115 (-176– -55) | -221 (-277− -165) |
FEV1 decline mL·yr−1 | Refƒ | 1.4 (-2.2−5.0) | 1.4 (-2.0−4.9) |
Smoking-adjusted model§ | |||
Baseline FEV1 mL | Ref | -80 (-139– -22) | -148 (-203– -93) |
FEV1 decline mL·yr−1 | Refƒ | 1.3 (-2.3−5.0) | 1.6 (-1.8−5.0) |
Data are presented as β (95% confidence interval), where β (the longitudinal linear regression coefficient) is effectively an adjusted mean, and relative to reference class. #: low: intermediate secondary education or less; intermediate: intermediate vocational or higher secondary education; and high: higher vocational or university education; ¶: n = 2,679 (5,760 records); +: including baseline age, age squared, height, height squared and interaction term of baseline age with time, with baseline age centred at 45 yrs; §: additionally adjusted for baseline smoking history in pack-years plus smoking status and number of cigarettes smoked per round, with smoking status in five categories: current smoker (smoking cigarettes: with filter, without filter, and unknown), former smoker, and never-smoker; ƒ: rate of FEV1 decline in the highly educated of 29.4 mL·yr−1 (95% CI 26.7–32.1 mL·yr−1) in basic model, and 29.6 mL·yr−1 (95% CI 26.8–32.3 mL·yr−1) in smoking-adjusted model.