Table 1.
Sample Demographic and Clinical Characteristics
| Characteristic | Analytic Sample (N = 30) |
Case Subjectsa (n = 17) |
Control Subjectsb (n = 13) |
|---|---|---|---|
| Age, mean ± SD, y | 62.6 ± 11.49 | 68.2 ± 7.41 | 55.2 ± 11.86 |
| Male sex | 10 (33) | 6 (35) | 4 (31) |
| Employment | |||
| Employed (full- or part-time) | 11 (37) | 1 (6) | 10 (77) |
| Retired | 10 (33) | 9 (53) | 1 (8) |
| Disabled | 6 (20) | 5 (29) | 1 (8) |
| Homemaker | 3 (10) | 2 (12) | 1 (8) |
| Education status | |||
| Less than high school | 10 (33) | 9 (53) | 1 (8) |
| High school | 7 (23) | 4 (24) | 3 (23) |
| Associate, technical, or trade school | 5 (17) | 1 (6) | 4 (31) |
| College degree or more | 7 (23) | 2 (12) | 5 (39) |
| Smoking history | |||
| Ever smoked (≥ 100 cigarettes) | 22 (73) | 17 (100.0) | 5 (39) |
| Current smoker | 6 (20) | 6 (35) | 0 |
| Spirometry, mean ± SD | |||
| FEV1, L | 1.7 ± 0.95 | 1.1 ± 0.51 | 2.5 ± 0.86 |
| FEV1 % predicted | 68.2 ± 30.30 | 48.4 ± 19.98 | 94.2 ± 19.84 |
| FEV1/FVC ratio | 0.6 ± 0.21 | 0.5 ± 0.15 | 0.8 ± 0.13 |
| GOLD classification, airflow limitation | |||
| No COPD | 10 (33) | 0 | 10 (77) |
| GOLD 1/2, mild/moderate | 9 (30) | 6 (35) | 3 (23) |
| GOLD 3/4, severe/very severe | 11 (37) | 11 (65) | 0 |
| COPD Foundation classification | |||
| SG0, normal | 9 (30) | 0 | 9 (69) |
| SG1, mild | 6 (20) | 3 (18) | 3 (23) |
| SG2/3, moderate/severe | 14 (47) | 14 (82) | 0 |
| SGU, undefined | 1 (3) | 0 | 1 (8) |
| COPD Assessment Test, mean ± SD | 16.6 ± 11.53 | 21.8 ± 10.1 | 8.5 ± 8.23 |
| mMRC | |||
| 0 | 7 (23) | 1 (6) | 6 (46) |
| 1 | 11 (37) | 6 (35) | 5 (39) |
| >2 | 11 (37) | 10 (59) | 1 (8) |
| Comorbid health conditions (any) | 28 (93) | 17 (100) | 11 (85) |
Data are presented as No. (%) unless otherwise indicated. GOLD = Global Initiative for Chronic Obstructive Lung Disease; mMRC = modified Medical Research Council; SG = spirometric grade.
a
Clinically significant COPD (FEV1 < 60% predicted or exacerbation risk).
b
COPD with FEV1 > 60% and exacerbation free > 12 months; or no known diagnosis or treatment for COPD and an FEV1/FVC ratio > 0.70.