The need for race-specific reference equations for pulmonary diffusing capacity for nitric oxide

BMC Pulmonary Medicine

Table 2 Multiple linear regression results for DLNO (5 s breath-hold)

N = 118	Unstandardized coefficients		Standardized coefficients		95% Confidence interval for beta		Collinearity statistics
N = 118	Beta	SE	Beta	t-statistic	Lower bound	Upper bound	Tolerance	VIF
Constant	− 1.69	39.67		− 0.043	− 80.3	76.9
Sex (0 = females; 1 = males)	40.97	4.79	0.59	8.55*	31.5	50.5	0.52	1.91
Age²	− 0.013	0.002	− 0.27	− 5.27*	− 0.018	− 0.008	0.93	1.07
Race (0 = black; 1 = white	12.44	3.54	0.18	3.52*	5.4	19.4	0.95	1.05
Height (cm)	0.78	0.245	0.22	3.17*	0.3	1.3	0.52	1.92

^*t-statistic was statistically significant (p < 0.01); SE = standard error; Durbin–Watson Statistic = 1.92; Overall R² = 0.72; Standard error of the estimate (SEE) = 18.8 mL/min/mmHg. Sex, Age², Race, and Height, accounted for approximately 60%, 6%, 5%, and 3% of the total variance in the model. ANOVA results were rounded to the nearest whole number except for Residual Mean Square error, which was rounded to two decimal places

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