Table 4.
Subgroup Analysis on Effects of Changes in Long Term Air Pollution (annual average) Concentrations on Changes in FeNO Levels Adjusted for Changes in Short-term Concentrations*
| Modifying Factor (N) | NO2 | PM2.5 | PM10 | O3 |
|---|---|---|---|---|
| Asthma | ||||
| No Asthma-No Asthma (1052) | 2.2 (0.22,4.12) † | 5.3 (1.68,8.83) ‡ | 0.1 (−2.07,2.24) | −0.5 (−4.24,3.30) |
| No Asthma-Asthma (23) | 3.1 (−2.38,8.64) | 1.8 (−9.1,12.65) | −4.6 (−9.76,0.65) | −2.7 (−10.79,5.33) |
| Asthma-Asthma (136) | 2.8 (0.32,5.31) † | 3.5 (−1.272,8.28) | 0.6 (−2.14,3.264) | −2.31 (−7.31,2.71) |
| Interaction p-value | 0.75 | 0.55 | 0.14 | 0.53 |
|
| ||||
| Allergy | ||||
| No Allergy-No Allergy (441) | 2.3 (0.32,4.46) † | 5.0 (1.20,8.78) ‡ | 0.7 (−1.60,3.09) | −1.0 (−5.04,2.98) |
| No Allergy-Allergy (44) | 1.1 (−2.83,5.02) | 4.7 (−2.54,12.02) | 1.2 (−3.60,5.98) | 0.9 (−5.06,6.78) |
| Allergy-Allergy (726) | 2.2 (0.23,4.28) † | 4.9 (1.25,8.62) ‡ | −0.1 (−2.35,2.04) | −0.756 (−4.60,3.09) |
| Interaction p-value | 0.78 | 0.99 | 0.41 | 0.77 |
|
| ||||
| Season | ||||
| Warm-Warm (226) | 2.0 (−0.50,4.50) | 6.9 (1.90,11.86) ‡ | −0.2 (−2.79,2.38) | 1.1 (−4.03,6.22) |
| Cold-Warm (368) | 2.4 (−0.90,5.74) | 3.4 (−0.77,7.66) | 0.5 (−2.7,3.74) | −0.7 (−5.92,5.59) |
| Warm-Cold (213) | 3.1 (0.36,5.81) † | 11.8 (3.22,20.30) ‡ | 0.4 (−2.55,3.30) | 3.3 (−3.80,10.58) |
| Cold-Cold (404) | 2.8 (−1.15,6.71) | 4.5 (−0.48,9.41) | 0.6 (−3.03,4.15) | −0.6 (−5.59,4.41) |
| Interaction p-value | 0.82 | 0.08 | 0.90 | 0.63 |
|
| ||||
| Gender | ||||
| Boys (571) | 2.5 (0.41,4.67) † | 4.2 (0.46,7.94) ‡ | 0.1 (−2.14,2.28) | −1.6 (−5.52,2.40) |
| Girls (640) | 2.2 (0.22,4.14) † | 5.7 (1.94,9.41) ‡ | 0.2 (−2.07,2.45) | −0.1 (−3.99,3.72) |
| Interaction p-value | 0.59 | 0.24 | 0.87 | 0.22 |
*
Results are scaled to the IQR values of 1.8 ppb (NO2), 2.4 μg/m3 (PM2.5), 3.4 μg/m3 (PM10), and 2.1 ppb (O3) of changes in annual average pollution levels between the two years of study. Estimates are adjusted for short-term effects of the same air pollutant. Models are also adjusted, as appropriate, for changes (or interactions with changes in age for time-independent covariates) in community, race/ethnicity, sex, asthma, asthma medication use, history of respiratory allergy, age, day of FeNO collection and season.
†
P<0.05
‡
P<0.01