Table 1.

Demographics of healthy children in whom spirometry measurements were obtained

	Black (B)	White (W)	Mean Difference (95%CI; B–W)
N (% male)	214 (40%)	186 (50%)
Age (yrs)	8.9 (1.7)	8.4 (1.6)	0.5 (0.2; 0.8)*
Height (cm)	137.1 (13.0)	131.2 (10.8)	5.9 (3.5; 8.2)
Height Z-score	0.7 (1.1)	0.3 (0.9)	0.5 (0.2; 0.7)***
Weight (kg)	36.2 (12.1)	29.7 (7.8)	6.4 (4.4; 8.5)
Weight Z-score	0.8 (1.0)	0.3 (0.9)	0.5 (0.3; 0.7)***
BMI	18.8 (3.7)	17.0 (2.2)	1.8 (1.2; 2.4)
BMI Z-score	0.7 (1.0)	0.3 (0.9)	0.4 (0.2; 0.6)***

Unless stated otherwise, results presented as mean (SD),

^*p<0.05,

^**p<0.005,

^***p<0.0005

Z-scores for weight, height and BMI were based on CDC growth charts.¹⁹