Table 1.
Descriptive characteristics of the study population by cohort.
| Cohorta | |||
|---|---|---|---|
| Totalb | TIDES | GAPPS | |
| (N = 453) | (N = 214) | (N = 239) | |
| Maternal race | |||
| White | 346 (76.4%) | 187 (87.4%) | 159 (66.5%) |
| Black | 20 (4.4%) | 0 (0%) | 20 (8.4%) |
| Asian | 24 (5.3%) | 15 (7.0%) | 9 (3.8%) |
| Native Hawaiian/Other Pacific Islander | 1 (0.2%) | 0 (0%) | 1 (0.4%) |
| American Indian/Alaska Native | 2 (0.4%) | 1 (0.5%) | 1 (0.4%) |
| Other | 26 (5.7%) | 17 (7.9%) | 9 (3.8%) |
| Multiple race | 16 (3.5%) | 1 (0.5%) | 15 (6.3%) |
| Missing | 18 (4.0%) | 18 (8.4%) | 0 (0%) |
| Maternal ethnicity | |||
| Hispanic or Latino | 38 (8.4%) | 17 (7.9%) | 21 (8.8%) |
| Not Hispanic or Latino | 401 (88.5%) | 197 (92.1%) | 204 (85.4%) |
| Missing | 14 (3.1%) | 0 (0%) | 14 (5.9%) |
| Maternal education | |||
| Less than high school | 14 (3.1%) | 11 (5.1%) | 3 (1.3%) |
| High school | 79 (17.4%) | 28 (13.1%) | 51 (21.3%) |
| College/technical school | 170 (37.5%) | 65 (30.4%) | 105 (43.9%) |
| Graduate or Professional degree | 190 (41.9%) | 110 (51.4%) | 80 (33.5%) |
| Maternal history of asthma | |||
| Yes | 60 (13.2%) | 24 (11.2%) | 36 (15.1%) |
| No | 365 (80.6%) | 177 (82.7%) | 188 (78.7%) |
| Missing | 28 (6.2%) | 13 (6.1%) | 15 (6.3%) |
| Maternal Delivery Age (years) | |||
| Mean (SD) | 32.1 (5.3) | 31.8 (5.4) | 32.3 (5.1) |
| Median (IQR) | 32 (29–36) | 32 (28–36) | 32 (29–36) |
| Missing | 29 (6.4%) | 0 (0%) | 29 (12.1%) |
| Child sex | |||
| Male | 246 (54.3) | 110 (51.4%) | 136 (56.9%) |
| Female | 207 (45.7%) | 104 (48.6%) | 103 (43.1%) |
| Preterm birth | |||
| Yes | 67 (14.8%) | 13 (6.1%) | 54 (22.6%) |
| No | 364 (80.4%) | 198 (92.5%) | 166 (69.5%) |
| Missing | 22 (4.9%) | 3 (1.4%) | 19 (7.9%) |
| Season of birth | |||
| Warm | 237 (52.3%) | 109 (50.9%) | 126 (52.7%) |
| Cold | 216 (47.7%) | 105 (49.1%) | 113 (47.3%) |
| Birthweight (grams) | |||
| Mean (SD) | 3,252 (705.6) | 3,387 (500.8) | 3,122 (839) |
| Median (IQR) | 3,316 (2940–3710) | 3,358 (3071–3700) | 3,274 (2755–3716) |
| Missing | 120 (26.5%) | 15 (7.0%) | 22 (9.2%) |
| Firstborn status | |||
| Yes | 130 (28.7%) | 35 (16.4%) | 90 (37.7%) |
| No | 305 (67.3%) | 172 (80.4%) | 138 (57.7%) |
| Missing | 18 (4.0%) | 7 (3.3%) | 11 (4.6%) |
| Ever bronchiolitisc | |||
| Yes | 31 (6.8%) | 14 (6.5%) | 17 (7.1%) |
| No | 302 (66.7%) | 185 (86.4%) | 117 (49.0%) |
| Missing | 120 (26.5%) | 15 (7.0%) | 105 (43.9%) |
| Child age at 4-6 visit (years) | |||
| Mean (SD) | 5.8 (0.7) | 6.2 (0.4) | 5.5 (0.7) |
| Median (IQR) | 6 (5.3–6.2) | 6.1 (6.0–6.2) | 5.4 (5.1–5.9) |
| Missing | 18 (4.0%) | 7 (3.3%) | 11 (4.6%) |
| Household size | |||
| <4 | 80 (17.7%) | 40 (18.7%) | 40 (16.7%) |
| 4 | 204 (45.0%) | 101 (47.2%) | 103 (43.1%) |
| 5 | 83 (18.3%) | 35 (16.4%) | 48 (20.1%) |
| >5 | 50 (11.0%) | 19 (8.9%) | 31 (13.0%) |
| Missing | 36 (7.9%) | 19 (8.9%) | 17 (7.1%) |
| Adjusted income ($USD) | |||
| Mean (SD) | $114,004 ($56,745) | $117,237 ($59,070) | $111,188 ($54,193) |
| Median (IQR) | $110,813 ($67,648–$172,511) | $110,813 ($67,676–$172,511) | $105,682 ($67,648–$147, 955) |
| Missing | 32 (7.1%) | 18 (8.4%) | 14 (5.9%) |
| Smoking self-report | |||
| Yes | 15 (3.3) | 10 (4.7%) | 5 (2.1%) |
| No | 436 (96.2%) | 104 (48.6%) | 232 (97.1%) |
| Missing | 2 (0.4%) | 0 (0%) | 2 (0.8%) |
| Averaged cotinined | |||
| Mean (SD) | 29.7 (169.2) | 40.7 (206.1) | 11.4 (79.2) |
| Median (IQR) | 0.01 (0.01–0.06) | 0.01 (0.01–0.07) | 0.01 (0.001–0.02) |
| Missing | 113 (24.9%) | 2 (0.9) | 111 (46.4%) |
| Postnatal second-hand smoke exposure | |||
| Yes | 127 (28.0%) | 121 (56.5%) | 16 (6.7%) |
| No | 300 (66.2%) | 93 (43.5%) | 207 (86.6%) |
| Missing | 16 (3.5%) | 9 (4.2%) | 16 (6.7%) |
| Cohort Site | |||
| GAPPS | |||
| Seattle, WA | 164 (36.2%) | 164 (68.6%) | |
| Yakima, WA | 75 (16.6%) | 75 (31.4%) | |
| TIDES | |||
| Minneapolis, MN | 56 (12.4%) | 56 (26.2%) | |
| Rochester, NY | 49 (10.8%) | 49 (22.9%) | |
| San Francisco, CA | 63 (12.9%) | 63 (29.4%) | |
| Seattle, WA | 46 (10.2%) | 46 (21.5%) | |
a
Percentages are within cohort.
b
Percentages are within total group.
c
Bronchiolitis history was not surveyed for the subset of GAPPS participants who completed the recall survey at age 4–6. Bronchiolitis was unavailable for N = 11 from the GAPPS age 8–9 recall group.
d
Measured in nanograms per milliliter (ng/mL). Cotinine was not measured for the subset of GAPPS participants who completed the recall survey at age 4–6. Cotinine was unavailable for N = 15 from the GAPPS age 8–9 recall group.