Table 1.
Baseline characteristics by distance of residence from nearest major roadway among women residing in the contiguous United States and Canada, Pregnancy Study Online (2013–2019)
| Characteristica | United States (n = 7,342) | Canada (n = 1,448) | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Distance from closest A1–A3 road (meters) | Distance from closest expressway, highway, or major road (meters) | |||||||||
| <50 | 50–99 | 100–199 | 200–399 | ≥400 | <50 | 50–99 | 100–199 | 200–399 | ≥400 | |
| Number of women | 1,046 | 863 | 1,488 | 1,750 | 2,195 | 204 | 161 | 291 | 375 | 424 |
| Age (years); mean | 30.1 | 30.3 | 29.9 | 30.0 | 29.8 | 29.0 | 29.9 | 29.6 | 29.4 | 29.6 |
| Race/ethnicity, % | ||||||||||
| Non-Hispanic White | 80.9 | 80.4 | 82.4 | 82.2 | 85.0 | 87.1 | 84.1 | 86.0 | 92.3 | 91.8 |
| Non-Hispanic Black | 4.7 | 3.9 | 4.0 | 3.9 | 3.4 | 1.5 | 1.5 | 2.1 | 0.6 | 0.2 |
| Non-Hispanic Asian | 2.7 | 2.9 | 2.0 | 1.6 | 1.0 | 3.5 | 4.0 | 3.7 | 1.3 | 1.4 |
| Hispanic | 8.2 | 8.7 | 7.6 | 7.8 | 6.2 | 3.4 | 3.1 | 3.0 | 1.9 | 1.9 |
| Other race/ethnicity | 3.5 | 4.2 | 4.0 | 4.5 | 4.4 | 3.7 | 7.3 | 5.1 | 3.9 | 4.7 |
| ≤12 years education, % | 6.4 | 6.5 | 6.7 | 4.8 | 6.2 | 5.8 | 5.1 | 5.9 | 3.9 | 4.7 |
| Household income <50,000 USD/year, % | 24.9 | 24.0 | 21.3 | 20.1 | 22.2 | 19.2 | 14.6 | 17.5 | 13.1 | 15.0 |
| BMI (kg/m2); mean | 28.3 | 28.0 | 28.0 | 28.3 | 28.8 | 26.9 | 27.5 | 27.8 | 27.2 | 27.2 |
| Physical activity (MET-hours/week); mean | 39.3 | 39.5 | 36.9 | 37.3 | 37.2 | 34.4 | 35.3 | 37.1 | 35.1 | 33.8 |
| Current regular smoker, % | 7.7 | 8.1 | 7.6 | 7.2 | 7.3 | 8.8 | 8.8 | 8.3 | 6.9 | 8.2 |
| Alcohol (drinks/week); mean | 3.4 | 3.3 | 3.1 | 3.2 | 3.0 | 3.3 | 2.9 | 3.2 | 3.2 | 3.2 |
| Sugar-sweetened soda (drinks/week); mean | 1.7 | 1.8 | 1.6 | 1.6 | 2.0 | 1.3 | 1.0 | 1.2 | 1.1 | 1.1 |
| Healthy Eating Index 2010 score; mean | 64.6 | 64.3 | 64.1 | 64.4 | 62.6 | 65.9 | 67.5 | 67.2 | 66.9 | 66.5 |
| Daily multivitamins/folic acid, % | 77.0 | 79.0 | 79.2 | 79.4 | 79.4 | 78.7 | 81.1 | 78.9 | 75.9 | 74.4 |
| <7 hours/night of sleep, % | 25.8 | 24.7 | 26.6 | 25.6 | 28.1 | 24.3 | 23.8 | 26.3 | 25.1 | 21.9 |
| Parous, % | 29.9 | 29.4 | 34.5 | 35.7 | 37.3 | 21.6 | 25.7 | 24.5 | 25.2 | 26.5 |
| Intercourse <1 time/week, % | 22.1 | 22.7 | 21.1 | 21.8 | 19.6 | 22.6 | 17.9 | 21.8 | 19.2 | 20.7 |
| Hormonal last contraception, % | 39.8 | 38.7 | 37.8 | 38.2 | 41.5 | 39.3 | 33.3 | 34.9 | 33.0 | 32.1 |
| History of infertility, % | 12.0 | 10.1 | 10.3 | 10.6 | 11.3 | 10.0 | 5.7 | 6.6 | 8.2 | 6.9 |
| Doing something to improve chances, % | 77.0 | 75.3 | 77.6 | 77.5 | 78.7 | 78.1 | 77.2 | 73.9 | 76.4 | 75.5 |
| Urban census tract, % | 89.3 | 92.0 | 93.0 | 92.4 | 72.5 | 73.7 | 87.0 | 80.7 | 81.9 | 74.4 |
| Tract-level median household incomeb | 58,000 | 58,000 | 59,100 | 58,800 | 63,700 | 71,800 | 73,800 | 73,000 | 77,400 | 88,800 |
| Tract-level % <high school education | 12.1 | 12.5 | 11.7 | 11.6 | 10.8 | 16.6 | 15.7 | 16.7 | 16.7 | 16.6 |
| Tract-level % unemployed | 4.9 | 5.0 | 4.9 | 4.9 | 4.5 | 7.7 | 8.1 | 8.1 | 7.8 | 7.4 |
| Tract-level % non-Hispanic White | 72.6 | 70.5 | 71.5 | 71.5 | 77.2 | 80.9 | 77.6 | 79.8 | 81.5 | 83.8 |
aWith the exception of age, all characteristics are standardized to the age of the cohort at baseline.
bUS results reported in USD; Canadian results reported in Canadian dollars.