Table 2 Baseline characteristics and incident density by the four risk groups
Characteristics | High-risk, n (%) | Medium–high-risk, n (%) | Low-medium-risk, n (%) | Low-risk, n (%) |
|---|---|---|---|---|
Age (years) | ||||
50–54 | 0 (0) | 0 (0) | 84 (1.8) | 4658 (97.5) |
55–59 | 46 (0.9) | 272 (5.7) | 4337 (94.7) | 118 (2.5) |
60–64 | 449 (8.9) | 4467 (93.6) | 90 (2.0) | 0 (0) |
65–69 | 3451 (68.8) | 6 (0.1) | 69 (1.5) | 0 (0) |
70–74 | 1072 (21.4) | 27 (0.6) | 0 (0) | 0 (0) |
Mean \(\pm\) SD | 67.2 \(\pm\) 3.0 | 61.7 \(\pm\) 2.0 | 57.0 \(\pm\) 2.1 | 52.3 \(\pm\) 1.5 |
Sex | ||||
Female | 30 (0.6) | 61 (1.3) | 210 (4.6) | 285 (6.0) |
Male | 4988 (99.4) | 4711 (98.7) | 4370 (95.4) | 4491 (94.0) |
Smoking intensity (pack years) | ||||
30–49 | 3090 (61.6) | 3168 (66.4) | 3218 (70.3) | 3402 (71.2) |
\(\ge\) 50 | 1928 (38.4) | 1604 (33.6) | 1362 (29.7) | 1374 (28.8) |
P50 (P25,P75) | 40.0 (35.0, 60.0) | 40.0 (32.0, 60.0) | 40.0 (30.0, 53.0) | 36.0 (30.0, 53.0) |
Self-reported history of tuberculosis | ||||
No | 4597 (91.6) | 4700 (98.5) | 4421 (96.5) | 4625 (96.8) |
Yes | 421 (8.4) | 72 (1.5) | 159 (3.5) | 151 (3.2) |
Self-reported history of emphysema | ||||
No | 4336 (86.4) | 4538 (95.1) | 4474 (97.7) | 4577 (95.8) |
Yes | 682 (13.6) | 234 (4.9) | 106 (2.3) | 199 (4.2) |
Incident density (/100,000 person-years) | 262 | 220 | 154 | 81 |