TABLE 1

Comparison of lung function measurements of enrolled participants and participants included in the analyses

VariablesAnalytical sampleEnrolled samplep-value
Age 18 yearsn=315n=839
 Lung function
  FVC (L)4.62 (4.04, 5.52)4.47 (3.93, 5.32)0.071
  FEV1 (L)4.11 (3.55, 4.74)3.91 (3.44, 4.51)0.0067
  FEV1/FVC0.88 (0.82, 0.93)0.88 (0.83, 0.92)0.37
 Height (cm)172.5 (164, 178.5)171 (164, 178)0.36
 BMI (kg·m−2)22.36 (20.32, 24.84)22.15 (20.27, 24.81)0.40
 Sex
  Male181 (57.46)396 (47.20)0.0019
  Female134 (42.54)443 (52.80)
 Smoking
  Non-smoker167 (53.02)462 (55.07)0.90
  Current smoker80 (25.40)205 (24.43)
  Past smoker64 (20.32)159 (18.95)
  Missing4 (1.27)13 (1.55)
Age 26 yearsn=268n=547
 Lung function
  FVC (L)4.66 (4.13, 5.57)4.72 (4.14, 5.69)0.76
  FEV1 (L)3.70 (3.33, 4.49)3.76 (3.33, 4.55)0.18
  FEV1/FVC0.81 (0.77, 0.84)0.81 (0.77, 0.85)0.81
 Height (cm)170 (164.45, 178)171 (164.4, 178.0)0.17
 BMI (kg·m−2)25.1 (22.30, 29.05)24.80 (22.0, 28.8)0.54
 Sex
  Male105 (39.18)236 (43.14)0.28
  Female163 (60.82)311 (56.86)
 Smoking
  Non-smoker145 (54.10)288 (52.65)0.021
  Current smoker61 (22.76)128 (23.40)
  Past smoker59 (22.01)101 (18.46)
  Missing3 (1.12)30 (5.48)

Data are presented as median (interquartile range) or n (%), unless otherwise stated. FVC: forced vital capacity; FEV1: forced expiratory volume in 1 s; BMI: body mass index. Bold font indicates statistical significance.