Table 2.
Effect of Combined Major Roadway Proximity on Asthma Symptoms†
| Unadjusted Analyses | Adjusted* Analyses | |||
|---|---|---|---|---|
| Effect estimates are based on each 100m farther away from major roadway | ||||
| OR (95% CI) n=350 |
p-value | OR (95% CI) n=350 |
p-value | |
|
Primary Outcome Components |
||||
| Maximum Symptom Days *** | 0.68 (0.53 – 0.87) | p<0.01 | 0.71 (0.58 – 0.87) | p<0.01 |
| Daytime Wheeze** | 0.70 (0.54 – 0.91) | p<0.01 | 0.76 (0.61 – 0.95) | p=0.02 |
| Limitations in Activities*** | 0.62 (0.42 – 0.90) | p=0.01 | 0.61 (0.43 – 0.88) | p<0.01 |
| Nighttime Wheeze | 0.71 (0.49 – 1.04) | p=0.08 | 0.79 (0.59 – 1.05) | p=0.10 |
| Secondary Outcomes | ||||
| Health Care Utilization*** | 0.69 (0.52 – 0.92) | p=0.01 | 0.63 (0.47 – 0.85) | p<0.01 |
| Missed School Days | 0.85 (0.41 – 1.78) | p=0.66 | 0.97 (0.54 – 1.74) | p=0.92 |
| Caregiver Plans Changed | 0.72 (0.41 – 1.25) | p=0.24 | 0.73 (0.43 – 1.24) | p=0.24 |
| Caregiver Lost Sleep | 0.69 (0.46 – 1.01) | p=0.06 | 0.75 (0.54 – 1.06) | p=0.10 |
| Composite Poor Asthma*** | 0.77 (0.65 – 0.92) | p<0.01 | 0.80 (0.69 – 0.94) | p<0.01 |
| Spirometry Outcomes |
β (95% CI) n=327 |
p-value |
β (95% CI) n=327 |
p-value |
| FEV1, % predicted | −1.02 (−4.57 – 2.54) | p=0.58 | −0.44 (−4.20 – 3.31) | p=0.82 |
| FVC, % predicted | −2.77 (−5.45 - −0.10) | p=0.04 | −2.26 (−5.15 – 0.64) | p=0.13 |
| FEV1/FVC, percent** | 1.39 (0.18 – 2.60) | p=0.03 | 1.39 (0.18 – 2.60) | p=0.03 |
| FEF25–75, % predicted | −2.60 (−10.76 – 5.56) | p=0.53 | −2.77 (−10.93 – 5.39) | p=0.51 |
FEV1: Forced expiratory volume in one second; FVC: Forced Vital Capacity; FEV1/FVC: The percent of forced expiratory volume in one second over forced vital capacity; FEF25–75: Forced expiratory flow at 25–75% of the forced vital capacity.
Adjusted for: age, sex, race/ethnicity, annual household income, environmental tobacco smoke, controller medication, recent upper respiratory infections, and seasonality. Models for FEV1, % predicted and FEF25–75, % predicted did not adjust separately for age, sex, and race/ethnicity as these are included in the percent prediction estimates.
p<0.05 in adjusted analyses;
p<0.01 in adjusted analyses.
Includes all study participants (n=1327 observations; n=350 participants) and corresponding spirometry outcomes (n=645 observations; n=327 participants)