| Total | Former Smoker | Current Smoker | P-value |
---|---|---|---|---|
N | 89 | 35 | 54 | Â |
Years of age, median (IQR) | 58 (54–65) | 65 (59–69) | 55 (51–60) | <.001 |
Male, n (%) | 54 (61%) | 25 (71%) | 29 (54%) | 0.12 |
Race or ethnic group, n (%) | ||||
 White | 51 (57%) | 24 (69%) | 27 (50%) | 0.12 |
 Black | 38 (43%) | 11 (31%) | 26 (48%) | 0.12 |
 Hispanic | 1 (1%) | 0 (0%) | 1 (2%) |  |
Smoking history median (IQR) | ||||
 Current cigarettes/day |  |  | 10 (5–20) |  |
 Age started smoking | 15 (13–18) | 15 (13–18) | 15 (13–17) | 0.34 |
 Years since quitting | 10 (4–15) | 10 (4–15) |  |  |
 Pack years (packs * years smoking) | 39 (25–56) | 39 (27–62) | 39 (23–53) | 0.66 |
COPD Characteristics n (%) | ||||
 COPD exacerbation, prior 12 months | 19 (21%) | 4 (11%) | 15 (28%) | 0.11 |
 FEV1 (%predicted) | 61 (53–70) | 57 (53–65) | 64 (53–71) | 0.18 |
 FEV1/FVC ratio | 0.56 (0.48–0.62) | 0.53 (0.46–0.59) | 0.57 (0.50–0.63) | 0.09 |
 DLCO (mL/mm/mmHg) | 15.7 (12.1–20.9) | 16.1 (11.9–21.2) | 15.7 (12.1–20.9) | 0.95 |
 TLC (Liters) | 6.0 (5.0–7.2) | 6.3 (5.3–7.4) | 5.7 (5.0–7.0) | 0.2 |
 SVC (Liters) | 3.3 (2.7–4.1) | 3.7 (2.7–4.2) | 3.2 (2.6–4.0) | 0.49 |
 FRC (Liters) | 3.5 (3.0–4.2) | 3.6 (3.0–4.1) | 3.5 (3.0–4.2) | 0.76 |
 RV (Liters) | 2.6 (2.2–3.2) | 2.7 (2.4–3.5) | 2.6 (1.9–3.0) | 0.09 |
 Pulse oximetry (%) | 96 (94–97) | 95 (93–97) | 96 (95–98) | 0.01 |
 Short acting beta-agonist (SABA) | 61 (69%) | 22 (63%) | 39 (72%) | 0.36 |
 LABA and inhaled corticosteroid | 40 (45%) | 17 (49%) | 23 (43%) | 0.66 |
 Long-acting anticholinergic | 26 (29%) | 11 (31%) | 15 (28%) | 0.81 |
 Aspirin | 22 (25%) | 14 (40%) | 8 (15%) | 0.01 |
Questionnairre scores (median (IQR) | ||||
 Medical Research Council Dyspnea | 2 (1–3) | 2 (1–3) | 2 (1–3) | 0.41 |
 St George’s Respiratory | 40 (26–56) | 39 (26–56) | 46 (26–62) | 0.42 |