Table 4

Differences in the calculated lower limit of normal (LLN) values for FVC, FEV₁ and FEV₁/FVC by race/ethnicities between the different reference equations*

	All	Caucasian	Black	NE Asian	SE Asian	Mixed/Other	P
n	406	229	20	21	92	44
LLN FVC differences (L)
Canadian equation—GLI-Race	0.29 (0.11, 0.49)	0.16 (0.08, 0.34)	0.66 (0.55, 0.95)†	−0.01 (–0.07, 0.07)†	0.49 (0.31, 0.71)†	0.47 (0.29, 0.62)†	<0.001
Canadian equation—GLI-Other	0.37 (0.25, 0.57)	0.38 (0.27, 0.60)	0.36 (0.29, 0.57)	0.35 (0.15, 0.51)	0.29 (0.15, 0.50)†	0.47 (0.29, 0.62)	<0.001
LLN FEV₁ differences (L)
Canadian equation—GLI-Race	0.22 (0.15, 0.33)	0.20 (0.14, 0.23)	0.59 (0.54, 0.74)†	0.05 (–0.03, 0.10)†	0.33 (0.21, 0.46)†	0.35 (0.30, 0.46)†	<0.001
Canadian equation—GLI-Other	0.36 (0.27, 0.43)	0.38 (0.31, 0.44)	0.37 (0.33, 0.43)	0.26 (0.18, 0.37)†	0.23 (0.14, 0.35)†	0.35 (0.30, 0.46)	<0.001
LLN FEV₁/FVC difference (%)
Canadian equation—GLI-Race	1.16 (–0.34, 1.90)	1.81 (1.31, 2.21)	1.07 (0.67, 1.40)†	−0.79 (–1.44,–0.11) †	−1.47 (–1.98,–0.80) †	0.10 (–0.24, 0.34)†	<0.001
Canadian equation—GLI-Other	0.13 (–0.35, 0.57)	0.03 (–0.50, 0.42)	0.12 (–0.16, 0.39)	0.28 (–0.51, 0.87)	0.57 (–0.07, 1.16)†	0.10 (–0.24, 0.34)	<0.001

Data are presented as median (IQR). P value is the result of overall by Kruskal-Wallis test.
*We analysed the data by classifying Asian participants as NE Asian (model 1) if they could not be classified clearly as either NE Asian or SE Asian.
†Bonferroni correction for multiple comparisons with p<0.05 compared with Caucasian group.
FEV₁, forced expiratory volume in 1 s; FVC, forced vital capacity; GLI, Global Lung Function Initiative; LLN, lower limit of normal; NE, North East; SE, South East.