Table 2. Association Between Mucus Plug Score and All-Cause Mortality in Participants With COPD.

	No.	Mucus plug score (No. of lung segments with mucus plugs)
		0 (n = 2585)	1-2 (n = 953)		≥3 (n = 825)
Mortality rate, % (95% CI)		34.0 (32.2-35.8)	46.7 (43.5-49.9)		54.1 (50.7-57.4)
Unadjusted mortality rate difference, % (95% CI)			1-2 vs 0: 12.7 (9.1-16.4)		≥3 vs 0: 20.1 (16.2-24.0)
Model		HR (95% CI)	HR (95% CI)	P value	HR (95% CI)	P value
Unadjusted model	4363	1 [Reference]	1.51 (1.34-1.69)	<.001	1.98 (1.76-2.22)	<.001
Adjusted modela	4166	1 [Reference]	1.15 (1.02-1.29)	.02	1.24 (1.10-1.41)	<.001
Plus coronary artery diseaseb	4166	1 [Reference]	1.16 (1.03-1.30)	.02	1.26 (1.11-1.43)	<.001
Plus chronic bronchitisc	4166	1 [Reference]	1.15 (1.02-1.30)	.02	1.25 (1.10-1.42)	<.001
Plus current asthmad	4166	1 [Reference]	1.15 (1.02-1.30)	.02	1.25 (1.10-1.41)	<.001
Plus exacerbations per yeare	3759	1 [Reference]	1.10 (0.96-1.25)	.17	1.20 (1.05-1.38)	.008
Plus BODE indexf	4060	1 [Reference]	1.14 (1.01-1.29)	.03	1.21 (1.06-1.37)	.004

Abbreviations: BODE, body mass index, obstruction, dyspnea, and exercise mortality risk score; COPD, chronic obstructive pulmonary disease; HR, hazard ratio.

^a Estimates are from multivariable Cox models. Adjustment included age (continuous), sex (reference: female), race and ethnicity (reference: non-Hispanic Black), body mass index (BMI, calculated as weight in kilograms divided by height in meters squared; continuous), pack-years of smoking (continuous), current smoking status (reference: former), postbronchodilator forced expiratory volume in the first second of expiration (FEV₁; continuous), and computed tomography measures of emphysema (measured as percentage of voxels <−950 Hounsfield units; continuous) and airway wall thickness (measured as the square root of the wall area of an ideal 10-mm-inner-perimeter airway; continuous).

^b Adjusted HRs included all variables from the adjusted model plus adjustment for coronary artery disease (reference: absence of coronary artery disease).

^c Adjusted HRs included all variables from the adjusted model plus adjustment for coronary artery disease and chronic bronchitis (reference: absence of chronic bronchitis).

^d Adjusted HRs included all variables from the adjusted model plus adjustment for coronary artery disease, chronic bronchitis, and history of current asthma (reference: absence of current asthma).

^e Adjusted HRs included all variables from the adjusted model plus adjustment for coronary artery disease, chronic bronchitis, history of current asthma, and the number of exacerbations per year (continuous).

^f Adjusted HRs included all variables from the adjusted model except FEV₁ and BMI plus adjustment for the BODE index (continuous).