Table 2.
Demographics and incidence of respiratory conditions * of study participants.
| Characteristics | Total (n = 953) |
Children without Respiratory Conditions (n = 377) | Children with Respiratory Conditions (n = 576) | p Value |
|---|---|---|---|---|
| Maternal | ||||
| Age at delivery, years (mean, standard deviation (SD)) | 31.5 (5.1) | 31.7 (5.2) | 31.4 (5.1) | 0.315 |
| Ethnicity (%) | 0.062 | |||
| Chinese | 57.5 | 61.7 | 54.7 | |
| Malay | 24.5 | 20.7 | 26.9 | |
| Indian | 18.1 | 17.6 | 18.4 | |
| Educational attainment (%) | 0.760 | |||
| University | 35.4 | 34.3 | 36.1 | |
| Post-secondary/Pre-university | 34.8 | 34.6 | 35 | |
| No education/Primary/Secondary | 29.8 | 31.1 | 28.9 | |
| Multipara (%) | 55.4 | 54.9 | 55.7 | 0.803 |
| Maternal smoking during pregnancy and environmental tobacco smoke (ETS) # (%) | 0.087 | |||
| 1. No | 54.0 | 57.9 | 51.5 | |
| 2. Low | 30.2 | 29.0 | 31.0 | |
| 3. Mild | 12.0 | 9.0 | 13.9 | |
| 4. High ETS or/and active smoker | 3.8 | 4.1 | 3.6 | |
| History of maternal atopy (%) | 37.8 | 32.3 | 41.3 | 0.005 |
| Pre-pregnancy BMI (mean, SD) | 22.7 (4.4) | 22.5 (4.1) | 22.9 (4.5) | 0.179 |
| Child | ||||
| Gestational age, weeks (mean, SD) | 38.3 (1.7) | 38.4 (1.6) | 38.2 (1.8) | 0.075 |
| Preterm (<37 weeks) (%) | 7.9 | 6.9 | 8.5 | 0.367 |
| Gender-boy (%) | 52.8 | 49.1 | 55.2 | 0.064 |
| Birth weight, grams (mean, SD) | 3090 (485) | 3104 (467) | 3081 (497) | 0.465 |
| Passive smoke exposure to 2 years (%) | 38.5 | 37.1 | 39.4 | 0.462 |
| Respiratory conditions * (%) | ||||
| Wheezing | 29.2 | 0 | 29.2 | |
| Bronchiolitis/bronchitis | 13.7 | 0 | 13.7 | |
| Pneumonia | 1.8 | 0 | 1.8 | |
| Prolonged cough | 15.1 | 0 | 15.1 | |
| Rhinitis | 44.5 | 0 | 44.5 | |
| Ear infection | 5.1 | 0 | 5.1 |
# never smoke and never exposed to ETS and cotinine level lower than detection limit (LOD); self-reported ETS exposure and cotinine; level < LOD; cotinine levels 0.17–13.99+ currently not smoking; cotinine levels > 14 or self-reported smoker.