Table 1.
Characteristics of study participantsa, by the presence of wheezing
| Characteristic | Non-wheezers (n=1,852) | Atopicb wheezers (n=156) | Non-atopicb wheezers (n=94) | p-value |
|---|---|---|---|---|
| Age (y), mean (SEc) | 38.9 (1.1) | 37.1 (2.4) | 39.9 (1.3) | <0.001 |
| Male sex (% [SE]) | 44.9 (0.04) | 55.7 (0.07) | 48.9 (0.04) | 0.3 |
| Race/ethnicity (% [SE]) | 0.01 | |||
| Non-Hispanic white | 70.3 (0.03) | 72.1 (0.05) | 80.4 (0.04) | |
| Non-Hispanic black | 11.9 (0.2) | 13.8 (0.03) | 4.9 (0.02) | |
| Mexican American | 9.7 (0.01) | 5.1 (0.01) | 3.3 (0.01) | |
| Other | 8.2 (0.01) | 9.0 (0.03) | 11.4 (0.02) | |
| Low SESd (% [SE]) | 12.6 (0.01) | 15.6 (0.04) | 10.9 (0.03) | 0.6 |
| Asthmae (% [SE]) | 7.5 (0.01) | 48.7 (0.08) | 36.2 (0.05) | <0.001 |
| Atopyb (% [SE]) | 43.2 (0.01) | 100 (0) | - | <0.001 |
| 2,5-Dichlorophenol concentration in urine (geometric mean, μg/L [95% CIf]) | 33.1 (27.4–39.9) | 30.0 (19.2–46.8) | 25.6 (16.0–41.1) | <0.001 |
| Lower tertile | 1.9 (1.6–2.3) | 2.4 (1.8–3.2) | 1.3 (0.7–2.4) | 0.1 |
| Mid-tertile | 12.9 (12.2–13.7) | 14.0 (11.6–16.9) | 11.5 (9.2–14.5) | <0.001 |
| Upper tertile | 142.6 (112.1–181.4) | 134.0 (74.6–240.4) | 115.8 (76.6–175.0) | <0.001 |
| 2,4-Dichlorophenol concentration in urine (geometric mean, μg/L [95% CI]) | 2.4 (2.1–2.8) | 2.4 (1.7–3.4) | 2.2 (1.5–3.1) | <0.01 |
| Lower tertile | 0.30 (0.28–0.34) | 0.35 (0.28–0.45) | 0.27 (0.22–0.34) | <0.001 |
| Mid-tertile | 1.18 (1.1–1.2) | 1.22 (1.1–1.4) | 1.20 (1.1–1.3) | <0.01 |
| Upper tertile | 6.0 (4.8–7.6) | 5.1 (3.3–8.1) | 6.1 (5.3–7.0) | <0.001 |
| Medications for wheezing g (% [SE]) | - | 52.4 (0.07) | 56.0 (0.05) | 0.7 |
| Wheezing during exercise h (% [SE]) | - | 48.5 (0.05) | 52.4 (0.06) | 0.7 |
| Missing work or school due to wheezing i (% [SE]) | - | 26.8 (0.04) | 16.8 (0.05) | 0.2 |
All estimates are weighted to the sampling weights
Atopy was defined as the presence of allergen specific IgE ≥0.35 kU/L to at least one environmental and/ or food allergen
SE – standard error
Percentage of participants with a poverty/income ratio of <1.0
Asthma was defined by the answer to the question: “Has a doctor or other health professional ever told that (you have/s/he/survey participant (SP) has) asthma?”
95% CI – 95% confidence interval
In the past 12 months, (have you/ has study participant) taken medication, prescribed by a doctor, for wheezing or whistling?
In the past 12 months has (your/ study participant’s) chest sounded wheezy during or after exercise or physical activity?
During the past 12 months, did (you/ study participant) miss any days of work or school due to wheezing or whistling?