Tables
- TABLE 1
General characteristics of population and proportions of subjects with spirometric data below the lower limit of normal (LLN) (i.e. with z-score value < −1.64) and above the upper limit of normal (ULN) (i.e. with z-score value >1.64) in subjects without respiratory disease
Men ECSC versus GLI Women ECSC versus GLI Men versus women Subjects n 904 1067 Age years 53.3±7.1 52.8±7.3 0.149 Age categories n (%) 0.580 40–45 years 142 (15.7) 192 (18.0) 45–50 years 186 (20.6) 228 (21.4) 50–55 years 176 (19.5) 208 (19.5) 55–60 years 192 (21.4) 211 (19.8) 60–65 years 208 (23.0) 228 (21.4) Height (m) 0.067 (1.757) 0.067 (1.636) <0.001 BMI kg·m−² 27.3±4.2 26.0±5.2 <0.001 Mean z-scores ECSC FVC 0.79±1.08 1.30±1.11 <0.001 FEV1 0.37±1.06 0.51±1.00 0.002 FEV1/FVC −0.17±0.82 −0.25±0.85 0.039 GLI FVC 0.18±1.00 #,*** 0.24±0.98 #,*** 0.194 FEV1 0.01±1.11 #,*** 0.03±1.00 #,*** 0.421 FEV1/FVC −0.32±0.87 #,*** −0.40±0.80 #,*** 0.064 Distribution of z-scores n (%) <LLN >ULN ECSC versus GLI <LLN >ULN ECSC versus GLI Men versus women ECSC FVC 12 (1.3) 189 (20.9) 4 (0.4) 387 (36.3) <0.001 FEV1 25 (2.8) 110 (12.2) 19 (1.8) 128 (12.0) 0.330 FEV1/FVC 42 (4.6) 3 (0.3) 62 (5.8) 5 (0.5) 0.456 GLI FVC 28 (3.1) 72 (8.0) ¶,*** 25 (2.3) 70 (6.6) ¶,*** 0.268 FEV1 45 (5.0) 63 (7.0) ¶,*** 47 (4.4) 61 (5.7) ¶,*** 0.417 FEV1/FVC 65 (7.2) 5 (0.6) ¶,*** 68 (6.4) 4 (0.4) ¶,* 0.644 Data are presented as mean±sd or n (%), unless otherwise stated. Z-scores calculated from European Community for Steel and Coal (ECSC) and Global Lung Function Initiative (GLI) reference equations. FVC: forced vital capacity; FEV1: forced expiratory volume in 1 s. #: paired t-test between z-scores obtained by ECSC and GLI equations; ¶: Bhapkar's test between distribution of z-scores. *: p<0.05; ***: p<0.001.