Table 3.

Agreement data for predicted thoracic gas volume

	Regression			Residual Plot
	R2	SEE	r	P	Mean difference (95% CI)
European American
Girls
TGV (adult)	0.56	0.37	-0.65	0.001	0.59 (-0.12;1.30)
TGV (child-specific)	0.61	0.35	-0.56	0.001	0.11 (-0.57;0.78)
Boys
TGV (adult)	0.72	0.47	-0.59	0.01	0.32 (-0.58;1.22)
TGV (child-specific)	0.73	0.46	-0.50	0.05	0.06 (-0.83;0.94)
African American
Girls
TGV (adult)	0.71	0.24	-0.06	0.78	0.71 (0.18;1.24)
TGV (child-specific)	0.73	0.23	-0.01	0.96	0.23 (-0.28;0.75)
Boys
TGV (adult)	0.65	0.29	0.00	0.99	0.26 (-0.44;0.96)
TGV (child-specific)	0.67	0.29	-0.03	0.90	-0.02 (-0.67;0.64)
European
Girls
TGV (adult)	0.64	0.42	-0.72	0.001	0.41 (-0.42;1.23)
TGV (child-specific)	0.76	0.35	-0.16	0.37	0.06 (-0.68;0.75)
Boys
TGV (adult)	0.79	0.46	-0.81	0.001	-0.23 (-1.24;0.78)
TGV (child-specific)	0.80	0.46	-0.16	0.27	-0.22 (-1.15;0.71)

TGV; Thoracic gas volume.

TGV (adult); Thoracic gas volume predicted using the adult-based proprietary equations (developed using Crapo et al. prediction of functional residual capacity and tidal volume constants for males and females) [18].

TGV (child-specific); Thoracic gas volume predicted using the child-specific equations of Fields et al. [16].

Dependent variable is the measured TGV.

r; The Pearson correlation coefficient between the regression residuals and the criterion; criterion is measured thoracic gas volume).

P value indicates whether the r value is significant and estimation bias is present.

SEE; Standard error of the estimate.