Table 1 Baseline characteristics of study subjects.
Total (n = 454) | Respiratory disease at an age of 6 months | p-valuea | |||
|---|---|---|---|---|---|
No (n = 379) | Yes (n = 75) | ||||
Maternal | |||||
Age (years), mean(SD) | 28.5 (8.0) | 28.8 (7.6) | 26.9 (9.8) | 0.071b | |
< 30 | 207 (45.6) | 168 (44.3) | 39 (52.0) | 0.476c | |
30–34 | 206 (45.4) | 176 (46.4) | 30 (40.0) | ||
≥ 35 | 41 (9.0) | 35 (9.2) | 6 (8.0) | ||
Education, n (%) | |||||
< university | 243 (53.5) | 204 (53.8) | 39 (52.0) | 0.772 | |
≥university | 211 (46.5) | 175 (46.2) | 36 (48.0) | ||
Income per month, n (%) | |||||
<$2000 | 104 (22.9) | 92 (24.3) | 12 (16.0) | 0.243 | |
$2000–4000 | 279 61.5) | 227 (59.9) | 52 (69.3) | ||
>$4000 | 71 (15.6) | 60 (15.8) | 11 (14.7) | ||
Prepregnancy BMI, mean (SD) | 21.3 (3.1) | 21.4 (3.1) | 21.1 (2.8) | 0.489 | |
History of allergy, n (%) | |||||
No | 418 (93.3) | 351 (94.1) | 67 (89.3) | 0.132 | |
Yes | 30 (6.7) | 22 (5.9) | 8(10.7) | ||
Exposure to SHS, n (%) | |||||
No | 286 (63.0) | 238 (62.8) | 48 (64.0) | 0.039 | |
Yes | 168 (37.0) | 141 (37.2) | 27 (36.0) | ||
Gestational age (weeks), mean (SD) | 39.1 (1.1) | 39.1 (1.1) | 39.0 (1.2) | 0.583 | |
Infant | |||||
Sex, n (%) | |||||
Male | 250 (55.1) | 203 (53.6) | 47 (62.7) | 0.148 | |
Female | 204 (44.9) | 176 (46.4) | 28 (37.3) | ||
Birth weight (grams), mean (SD) | 3329 (374.5) | 3331 (375.7) | 3315 (370.4) | 0.725 | |
