Skip to main content

Advertisement

Table 1 Characteristics of COPD cases (GOLD stage 2 or greater) with and without physician-diagnosed asthma.

From: The clinical features of the overlap between COPD and asthma

  COPD Only COPD and Asthma p-value
Total Subjects 796 119 --
Race:    
Non-Hispanic white 672 (84.4) 79 (66.4) < 0.0001
African American 124 (15.6) 40 (33.6)  
Gender    
Male 423 (53.1) 61 (51.3) 0.77
Female 373 (46.9) 58 (48.7)  
Age, years 64.7 (8.2) 61.3 (8.9) 0.0001*
Pack-years of smoking 55.1 (27.3) 43.7 (20.7) < 0.0001*
Current smoker 270 (34.2) 46 (38.7) 0.35
BMI kg/m2 27.8 (6.0) 28.1 (6.7) 0.87*
GOLD Stage    
2 408 (51.3) 61 (51.3) 0.99**
3 251 (31.5) 38 (31.9)  
4 137 (17.2) 20 (16.8)  
BODE Index 3.0 (2.1) 3.2 (1.9) 0.28*
SGRQ 38.6(20.5) 44.0 (21.9) 0.0075*
6MWT (ft) 1140.2 (431.9) 1158.8 (430.1) 0.78*
Severe exacerbations 140 (17.6) 39 (32.8) 0.0003
Frequent exacerbations 114 (18.0) 41 (42.7) < 0.0001
Hay fever 204 (27.8) 65 (57.0) < 0.0001
Inhaled corticosteroid use 387 (49.4) 80 (69.0) 0.25***
FEV1 % predicted 49.4 (18.4) 49.2 (17.5) 0.85*
FVC % predicted 76.6 (17.9) 78.3 (17.3) 0.23*
FEV1/FVC 0.48 (0.13) 0.48 (0.12) 0.62*
Presence of bronchodilator response, ATS definition 270 (36.0) 46 (41.1) 0.30
Post bronchodilator % change in FEV1 8.7 (12.1) 10.2 (12.5) 0.33*
Percent Emphysema, -950HU 15.8 (13.5) 13.7 (12.3) 0.18*
Percent gas-trapping, -856HU 42.1 (20.3) 43.1 (20.5) 0.69*
Airway wall thickness Pi10 3.78 (0.12) 3.80 (0.14) 0.34*
  1. Values are presented as mean (SD) or N (%).
  2. Abbreviations and definitions: COPD = chronic obstructive pulmonary disease; Hay fever = self report of a history of hay fever; 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; FEV1 = forced expiratory volume in 1 second; FVC = forced vital capacity; Bronchodilator response = an increase in FEV1 of > 12% and 200 ml after administrator of bronchodilator; Pi10 = square root wall area of a hypothetical airway of 10 mm internal perimeter. Data compared using Fisher's exact test unless otherwise stated. *Wilcoxon rank sum analysis. **Chi-square analysis. ***p value adjusted for FEV1.