Table 4.

Standard multiple regression

Independent variables	Unstandardised coefficients B (SE)	95% CI	Standardised coefficients β	Semipartial correlations	p Value
Postbronchodilator FEV1 (% predicted)	−0.09 (0.03)	−0.16 to −0.02	−0.32	−0.28	0.008
Sputum neutrophils AUC (%)	0.12 (0.05)	0.01 to 0.22	0.26	0.28	0.03
Disease duration (years)	0.02 (0.04)	−0.07 to 0.10	0.05	0.04	0.70
Modified JACS	0.55 (0.69)	−0.82 to 1.92	0.09	0.09	0.42

Dependent variable is RB1 %WA (n=91).

Model R²=0.27*, adjusted R²=0.23, R=0.52, p=0.001.

*Unique variance=0.16; shared variance=0.11.

Model equation: RB1 %WA =66.02–0.09 (postbronchodialator FEV₁% predicted) +0.12 (sputum neutrophils AUC(%)).

Standard multiple regression using ‘enter’ method.

Unstandardised coefficients are used to construct a regression equation. Standardised coefficients are used to compare the unique contribution of each independent variable. Semipartial correlation coefficient squared indicates the contribution of the independent variable to the total R².

AUC, area under the curve per unit time; FEV₁, forced expiratory volume in 1 s; FVC, forced vital capacity; JACS, Juniper Asthma Control Score; RB1, right upper lobe apical segmental bronchus; WA, wall area.