Table 2.
Odds ratios (OR) and 95% confidence intervals (CIs) for asthma occurrence according to the level of greenness exposure before the age of 18.
| Greenness Exposure | Model 1 | Model 2 | ||
|---|---|---|---|---|
| OR (95% CI) | p-Value | OR (95% CI) | p-Value | |
| 0–20% | Reference | Reference | ||
| 21–40% | 1.17 (1.06–1.30) | 0.0027 | 1.17 (1.06–1.30) | 0.0027 |
| 41–60% | 1.28 (1.12–1.46) | 0.0003 | 1.28 (1.12–1.46) | 0.0002 |
| 61–80% | 1.32 (1.13–1.53) | 0.0003 | 1.34 (1.15–1.56) | 0.0002 |
| 81–100% | 1.09 (0.91–1.31) | 0.3674 | 1.10 (0.92–1.32) | 0.3142 |
| p for trend | 0.0393 | 0.0289 | ||
| Males | ||||
| 0–20% | Reference | Reference | ||
| 21–40% | 1.19 (1.04–1.37) | 0.0128 | 1.19 (1.04–1.37) | 0.0137 |
| 41–60% | 1.27 (1.06–1.51) | 0.0081 | 1.26 (1.06–1.50) | 0.0085 |
| 61–80% | 1.35 (1.10–1.64) | 0.0032 | 1.35 (1.11–1.65) | 0.0029 |
| 81–100% | 1.12 (0.88–1.43) | 0.3563 | 1.12 (0.88–1.43) | 0.3439 |
| p for trend | 0.0742 | 0.0750 | ||
| Females | ||||
| 0–20% | Reference | Reference | ||
| 21–40% | 1.14 (0.97–1.34) | 0.1021 | 1.15 (0.98–1.35) | 0.0936 |
| 41–60% | 1.28 (1.05–1.57) | 0.0156 | 1.30 (1.06–1.58) | 0.0102 |
| 61–80% | 1.28 (1.02–1.62) | 0.0371 | 1.32 (1.04–1.67) | 0.0213 |
| 81–100% | 1.05 (0.79–1.39) | 0.7491 | 1.07 (0.81–1.41) | 0.6433 |
| p for trend | 0.2702 | 0.1915 | ||
Model 1 was adjusted for urbanization level, frequency of healthcare provider visits, mean township family income, CO, and PM2.5. Model 2 was adjusted for urbanization level, frequency of healthcare providers visits, mean township family income, NO2, and PM2.5. The OR and 95% CI values were estimated using a conditional logistic regression model. The p-trends were calculated using the continuous scale of the level of greenness exposure in the corresponding models.