Table 2.

Associations of BDR categories with clinical, functional, and radiographic features at enrollment in subjects with chronic obstructive pulmonary disease (n = 3,340)

	Chronic Bronchitis		MMRC		6-MWT (ft)		Pi10 (mm)
	OR (95% CI)	P Value	Coef (95% CI)	P Value	Coef (95% CI)	P Value	Coef (95% CI)	P Value
No-BDR	Ref		Ref		Ref		Ref
FEV1-BDR	1.30 (0.91 to 1.85)	0.15	0.09 (−0.09 to 0.27)	0.31	30.6 (−19.6 to 80.7)	0.23	0.01 (−0.01 to 0.03)	0.34
FVC-BDR	0.94 (0.73 to 1.18)	0.58	0.05 (−0.07 to 0.16)	0.41	6.1 (−25.88 to 38.1)	0.71	0.01 (−0.003 to 0.02)	0.16
Combined-BDR	1.24 (0.96 to 1.59)	0.09	−0.09 (−0.22 to 0.04)	0.17	70.8 (35.09 to 106.4)	<0.001	0.04 (0.02 to 0.05)	<0.001
ATS-BDR*	1.10 (0.92 to 1.31)	0.28	0.01 (−0.08 to 0.09)	0.87	33.5 (9.5 to 57.5)	0.01	0.02 (0.01 to 0.03)	<0.001
	% Emphysema		% Gas Trapping		FRC% Predicted		TLC% Predicted
	Coef (95% CI)	P Value	Coef (95% CI)	P Value	Coef (95% CI)	P Value	Coef (95% CI)	P Value
No-BDR	Ref		Ref		Ref		Ref
FEV1-BDR	−0.76 (−2.19 to 0.67)	0.30	−−0.16 (−2.27 to 1.96)	0.88	1.41 (−2.52 to 5.35)	0.48	0.26 (−2.18 to 2.70)	0.84
FVC-BDR	0.13 (−0.76 to 1.02)	0.77	1.47 (0.15 to 2.78)	0.03	4.37 (1.91 to 6.82)	<0.001	1.53 (0.003 to 3.05)	0.0496
Combined-BDR	−1.67 (−2.68 to −0.65)	0.001	1.41 (−0.08 to 2.89)	0.06	5.10 (2.33 to 7.87)	<0.001	1.78 (0.05 to 3.51)	0.043
ATS-BDR*	−0.65 (−1.32 to 0.03)	0.059	1.18 (0.18 to 2.17)	0.02	4.14 (2.28 to 5.99)	<0.001	1.40 (0.25 to 2.55)	0.02

Definition of abbreviations: 6-MWT = 6-minute-walk test; ATS = American Thoracic Society; ATS-BDR = increase in prebronchodilator FEV₁ and/or FVC ≥12% and ≥200 ml after bronchodilator administration; BDR = bronchodilator response; CI = confidence interval; Coef = coefficient; combined-BDR = an increase in both FEV₁ and FVC ≥12% and ≥200 ml after bronchodilator administration; FEV₁ = forced expiratory volume in 1 second; FEV₁-BDR = increase in FEV₁ ≥12% and ≥200 ml but a change in FVC <12% and 200 ml after bronchodilator administration; FRC = functional residual capacity; FVC = forced vital capacity; FVC-BDR = increase in FVC ≥12% and ≥200 ml but a change in FEV₁ <12% and 200 ml after bronchodilator administration; MMRC = Modified Medical Research Council; no-BDR = a change in both FEV₁ and FVC <12% and <200 ml after bronchodilator administration; OR = odds ratio; Pi10 = square root of wall area for a hypothetical airway with an internal perimeter of 10 mm; Ref = reference; TLC = total lung capacity.

For % emphysema and TLC% predicted analysis, data were available for 3,127 subjects. For % gas trapping and FRC% analysis, data were available for 2,788 subjects. For 6-MWT data analysis, data were available for 3,264 subjects.

All models included the following covariates: age, sex, race, smoking status, smoking pack-years, body mass index, and post-bronchodilator FEV₁% predicted.

^*Multivariable linear and logistic regression models with ATS-BDR binary variable = BDR according to ATS guidelines; Yes or No as the independent variable.