Table 2.

Association of concurrent asthma diagnosis and COPD severity outcomes in COPD subjects.

Outcome	Additional Covariates	β(SE)/OR(CI)	p-value
BODE Index	age, gender, pack-years and race	0.29 (0.21)	0.17
SGRQ	age, gender, pack-years and race	5.2 (2.0)	0.009
6MWT, ft	age, gender, pack-years and race	31.6 (40.5)	0.43
Bronchodilator Response	age, gender, pack-years, and race	1.40[0.92, 2.13]	0.12
Severe exacerbations	age, gender, pack-years and race	1.93 [1.24, 3.02]	0.004
Frequent exacerbations	age, gender, pack-years and race	3.55 [2.19, 5.75]	< 0.0001
Number of exacerbations	age, gender, pack-years and race	0.68 (0.12)	< 0.0001
Percent Emphysema, -950HU	BMI, age, gender, pack-years, race and CT scanner*	-0.45 (1.23)	0.71
Percent gas-trapping, -856HU	BMI, age, gender, pack-years, race and CT scanner	4.31 (1.88)	0.02
Airway wall thickness Pi10	BMI, age, gender, pack-years, race and CT scanner	0.016 (0.013)	0.21

Abbreviations and definitions: COPD = chronic obstructive pulmonary disease; BODE index = body mass index, airflow obstruction, dyspnea and exercise capacity index; SGRQ = St George's Respiratory Questionnaire; 6MWT = 6 minute walk test; Severe Exacerbations = presence of COPD exacerbation resulting in presentation to emergency room or hospital admission in year prior to presentation; Frequent exacerbations = two or more COPD exacerbations in the year prior to enrollment; Number of exacerbations = number of COPD exacerbations in the year prior to enrollment; Pi10 = square root wall area of a hypothetical airway of 10 mm internal perimeter. *Siemens 64 Sensation scanners gave aberrant lung density measurements and therefore this scanner type was adjusted as a covariate.