Table 1.
Baseline Characteristics of Individuals with a Smoking History
| All (N = 10,132) |
Normal Spirometry (n = 4,387) |
PRISm (n = 1,262) |
GOLD 1–2 (n = 2,713) |
GOLD 3–4 (n = 1,770) |
|
|---|---|---|---|---|---|
| Age, yr | 59.5 ± 9.0 | 56.6 ± 8.4 | 57.2 ± 8.2 | 62.3 ± 8.9 | 64.2 ± 8.1 |
| Female, % | 4,723 (46.6) | 2,067 (47.1) | 679 (53.8) | 1,230 (45.3) | 747 (42.2) |
| Black, % | 3,366 (33.2) | 1,807 (41.2) | 541 (42.9) | 660 (24.3) | 358 (20.2) |
| Body mass index, kg/m2 | 28.8 ± 6.3 | 28.9 ± 5.8 | 31.9 ± 7.3 | 28.3 ± 5.9 | 27.3 ± 6.3 |
| Currently smoking, % | 5,364 (52.9) | 2,617 (59.7) | 804 (63.7) | 1,394 (51.4) | 549 (31.0) |
| Smoking pack-years | 44.2 ± 25.0 | 37.2 ± 20.2 | 42.6 ± 24.2 | 49.0 ± 26.3 | 55.4 ± 28.1 |
| Postbronchodilator FEV1, L | 2.2 ± 0.9 | 2.9 ± 0.7 | 2.1 ± 0.5 | 2.1 ± 0.7 | 1.0 ± 0.4 |
| Postbronchodilator FEV1, % predicted | 76.3 ± 25.5 | 97.4 ± 11.5 | 70.2 ± 8.4 | 72.5 ± 14.5 | 34.2 ± 10.0 |
| Postbronchodilator FEV1/FVC, % | 66.7 ± 16.2 | 78.7 ± 5.2 | 76.6 ± 4.9 | 60.3 ± 7.7 | 39.8 ± 10.4 |
| BODE index | 1 [0–3] | 0 [0–1] | 1 [0–3] | 1 [0–3] | 5 [4–7] |
| ⩾2 respiratory exacerbations in yr before study enrollment, n (%)* | 916 (9.0) | 119 (2.7) | 94 (7.4) | 290 (10.7) | 413 (23.3) |
| SGRQ total score ⩾ 25, n (%) | 4,731 (46.7) | 1,142 (26.0) | 643 (51.0) | 1,359 (50.1) | 1,587 (89.7) |
| mMRC score ⩾ 2, n (%) | 4,239 (41.8) | 1,027 (23.4) | 589 (46.7) | 1,140 (42.0) | 1,483 (83.8) |
| Chronic bronchitis, n (%) | 1,940 (19.1) | 551 (12.6) | 226 (17.9) | 647 (23.8) | 516 (29.2) |
| Self-reported coronary artery disease, n (%) | 654 (6.5) | 170 (3.9) | 87 (6.9) | 234 (8.6) | 163 (9.2) |
| Self-reported congestive heart failure, n (%) | 322 (3.2) | 58 (1.3) | 59 (4.7) | 84 (3.1) | 121 (6.8) |
| Self-reported diabetes mellitus, n (%) | 1,328 (13.1) | 506 (11.5) | 273 (21.6) | 312 (11.5) | 237 (13.4) |
| Personal history of cancer (before enrollment), n (%) | 494 (4.9) | 158 (3.6) | 43 (3.4) | 159 (5.9) | 134 (7.6) |
| Family history of cancer, n (%) | 3,766 (37.2) | 1,518 (34.6) | 525 (41.6) | 1,017 (37.5) | 706 (39.9) |
| Emphysema on chest CT, % of total lung volume† | 2.2 [0.7–7.3] | 1.1 [0.5–2.8] | 0.7 [0.3–1.8] | 4.1 [1.5–9.5] | 18.8 [7.6–30.2] |
| Pi10, mm‡ | 3.68 ± 0.13 | 3.65 ± 0.11 | 3.73 ± 0.13 | 3.67 ± 0.13 | 3.75 ± 0.14 |
Definition of abbreviations: BODE = Body mass index, airflow Obstruction, Dyspnea severity, Exercise capacity index; CT = computed tomography; GOLD = Global Initiative for Chronic Obstructive Lung Disease spirometry grade; mMRC = modified Medical Research Council dyspnea score; PRISm = preserved ratio impaired spirometry; SGRQ = St. George’s Respiratory Questionnaire.
Values represent counts (proportions) for categorical variables and means ± standard deviations or medians [interquartile intervals] for continuous variables.
Respiratory exacerbations were defined as those requiring treatment with antibiotics and/or systemic corticosteroids.
Emphysema is defined as the extent of low attenuation area (voxels <−950 Hounsfield Units at total lung capacity) as a percent of total lung volume (available for 9,419 participants).
Pi10 is a standardized measure of airway wall thickness on CT, defined as the square root of the wall area of a theoretical airway with an internal perimeter of 10 mm (available for 9,358 participants).