Table 3.
Subgroup analysis.
| DII | Sample Size | Early COPD | p-Value |
|---|---|---|---|
| Age | |||
| 20–29 | 1153 | 1.820 (0.735, 4.503) | 0.1954 |
| 30–39 | 1187 | 2.024 (0.699, 5.855) | 0.1934 |
| 40–49 | 1097 | 0.741 (0.146, 3.754) | 0.7177 |
| Sex | |||
| Females | 1664 | 2.325 (0.999, 5.410) | 0.0502 |
| Males | 1773 | 1.132 (0.435, 2.944) | 0.7988 |
| PIR | |||
| <1.85 | 1576 | 2.350 (1.010, 5.470) * | 0.0474 |
| ≥1.85 | 1861 | 1.077 (0.416, 2.784) | 0.8789 |
| Health insurance coverage | |||
| No | 1136 | 1.878 (0.705, 5.000) | 0.2072 |
| Yes | 2301 | 1.690 (0.742, 3.852) | 0.2117 |
| Sedentary activity | |||
| <3 h | 712 | 2.259 (0.629, 8.110) | 0.2114 |
| 3–6 h | 1256 | 1.223 (0.423, 3.542) | 0.7100 |
| ≥6 h | 1469 | 1.867 (0.678, 5.145) | 0.2272 |
| Smoking exposure (pack-years) | |||
| 0 | 2129 | 1.475 (0.635, 3.429) | 0.3664 |
| <10 | 848 | 3.689 (1.133, 12.012) * | 0.0303 |
| ≥10 | 460 | 0.417 (0.082, 2.126) | 0.2927 |
| Smokers living in the home | |||
| 0 | 1379 | 0.754 (0.245, 2.317) | 0.6219 |
| 1–2 | 551 | 3.550 (0.946, 13.319) | 0.0604 |
| ≥3 | 83 | 0.129 (0.002, 9.767) | 0.3531 |
| Mineral dusts | |||
| No | 2293 | 2.315 (1.117, 4.800) * | 0.0240 |
| Yes | 1144 | 0.731 (0.196, 2.721) | 0.6401 |
| Fumes from machinery or engines | |||
| No | 2529 | 1.800 (0.890, 3.639) | 0.1018 |
| Yes | 908 | 1.416 (0.349, 5.735) | 0.6262 |
| Wheezing | |||
| No | 2973 | 1.298 (0.626, 2.693) | 0.4833 |
| Yes | 464 | 4.016 (1.157, 13.947) * | 0.0286 |
| Asthma | |||
| No | 3069 | 1.702 (0.841, 3.444) | 0.1393 |
| Yes | 368 | 1.796 (0.433, 7.452) | 0.4197 |
| History of emphysema, bronchitis or asthma during childhood | |||
| No | 2549 | 1.180 (0.556, 2.505) | 0.6668 |
| Yes | 893 | 4.277 (1.362, 13.430) * | 0.0128 |
Notes: The results of subgroup analysis. p-Value: * p < 0.05.