Table 3. Sample clinical characteristics.
| Characteristic | Total (N=50) | COPD (Groups 1 & 2) (N=20) | Risk, no COPD (Groups 3 & 4) (N=30) |
|---|---|---|---|
|
Smoking status and history
| |||
| Never smoked, n (%) | 17 (34%) | 3 (15%) | 14 (47%) |
| Smoked cigarettes, n (%) | 32 (64%) | 17 (85%) | 15 (50%) |
| Former, n (%) | 16/32 (50%) | 6/17 (35%) | 10/15 (67%) |
| Current, n (%) | 16/32 (50%) | 11/17 (65%) | 5/15 (33%) |
| Age started smoking, mean (s.d.) | 17 (4) | 17 (5) | 17 (4) |
| Duration of smoking (years) | 33 (13) | 37 (10) | 29 (14) |
| Pack-yearsa | 40 (32) | 44 (34) | 34 (30) |
|
Other risk factors, n (%) Yes
| |||
| History of asthma | 20 (40%) | 9 (45%) | 11 (37%) |
| Exposure (smoke, dust, gas, air) | 41 (82%) | 18 (90%) | 23 (77%) |
| Colds move to chest | 35 (70%) | 16 (80%) | 19 (63%) |
| Childhood breathing conditions | 7/49 (14%) | 3/19 (16%) | 4 (13%) |
| Family history of breathing problems | 22 (44%) | 9 (45%) | 13 (43%) |
|
Breathing-related symptoms
b
, n (%)
| |||
| None | 3 (6%) | 1 (5%) | 2 (7%) |
| Chest symptomsc | 26 (52%) | 13 (65%) | 13 (42%) |
| Cough | 28 (56%) | 15 (75%) | 13 (43%) |
| Shortness of breath (overall) | 42 (84%) | 16 (80%) | 26 (87%) |
| With strenuous activity | 38 (76%) | 15 (75%) | 23 (77%) |
| With light activity | 25 (50%) | 13 (65%) | 12 (40%) |
| At rest | 9 (18%) | 5 (25%) | 4 (13%) |
|
Breathing events past year, n (%)
| |||
| None | 18 (36%) | 3 (15%) | 15 (50%) |
| Cold | 18 (36%) | 13 (65%) | 5 (17%) |
| Chest infection or pneumonia | 16 (32%) | 10 (50%) | 6 (20%) |
|
Breathing event impact, n (%)
| |||
| Missed work or school | 9 (18%) | 5 (25%) | 4 (13%) |
| Clinic visit | 15 (30%) | 5 (25%) | 10 (33%) |
| Emergency room visit/urgent care | 10 (20%) | 6 (30%) | 4 (13%) |
| Hospitalisation | 3 (6%) | 2 (10%) | 1 (3%) |
|
Non-respiratory health conditions, n (%)
| |||
| None | 7 (14%) | 0 (0%) | 7 (23%) |
| Cardiovascular | 20 (40%) | 8 (40%) | 12 (40%) |
| Metabolic | 7 (14%) | 0 (0%) | 7 (23%) |
| Musculoskeletal | 14 (28%) | 9 (45%) | 5 (17%) |
| Other (e.g., GI, cancer) | 17 (34%) | 5 (25%) | 12 (40%) |
|
Health status, mean (s.d.), median
| |||
| SF-36—Physical Component Summary (PCS) | 38 (12); 37 | 36 (13)d; 37 | 39 (12)d; 37 |
| SF-36—Mental Component Summary (MCS) | 47 (13); 50 | 46 (11)e; 46 | 47 (14)e; 51 |
| COPD Assessment Test (CAT) | 17 (9); 18 | 19 (9)f; 19 | 16 (8)f; 17 |
Abbreviations: COPD, chronic obstructive pulmonary disease; GI, gastrointestinal; NS, not significant.
a
Pack-years=(cigarettes per day/20 cigarettes per pack)×duration of smoking (years).
b
Categories are not mutually exclusive.
c
Chest congestion, discomfort, tightness, pain or wheeze.
d
Scale: 0–100; higher scores are better; t=0.91: COPD versus non-COPD, NS, P=0.37.
e
Scale: 0–100; higher scores are better t=0.28: COPD versus non-COPD, NS, P=0.78.
f
Scale: 0–100; higher scores are worse t=1.49: COPD versus non-COPD, NS, P=1.4.