Baseline educational level# in relation to baseline forced expiratory volume in 1 s (FEV1) and FEV1 decline during follow-up in females¶ (linear mixed-effects model)
| Educational level | |||
| High | Intermediate | Low | |
| Basic model+ | |||
| Baseline FEV1 mL | Ref | -25 (-73– 23) | -75 (-117– -34) |
| FEV1 decline mL·yr−1 | Refƒ | 2.0 (-0.9–5.0) | 3.4 (0.9–6.0) |
| Smoking-adjusted model§ | |||
| Baseline FEV1 mL | Ref | -15 (-61– 31) | -47 (-87– -6) |
| FEV1 decline mL·yr−1 | Refƒ | 1.9 (-1.0–4.8) | 3.3 (0.7–5.8) |
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 = 3,026 (6,365 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 21.3 mL·yr−1 (95% CI 19.1–23.5 mL·yr−1) in basic model, and 21.8 mL·yr−1 (95% CI 19.5–24.1 mL·yr−1) in smoking-adjusted model.