Table 1 Baseline characteristics of the participants (n = 88,567)
Analyzed (n = 65,568) | [Missing] | Not analyzed (n = 22,999) | [Missing] | Effect sizea | |
|---|---|---|---|---|---|
Males (%) | 33,416 (51.0) | 0 | 11,990 (52.1) | 0 | 0.01 |
Gestational age, weeks (SD) | 39.2 (1.6) | 0 | 39.2 (1.7) | 0 | 0.02 |
Birthweight, g (SD) | 3,011 (418) | 0 | 3,021 (439) | 0 | 0.01 |
Maternal age, years (SD) | 31.6 (4.8) | 0 | 30.7 (5.2) | 4 | 0.08 |
Caesarean section (%) | 12,771 (19.5) | 135 | 4,697 (20.5) | 43 | 0.01 |
Maternal allergic diseases (%) | 36,113 (55.3) | 245 | 12,387 (54.3) | 183 | 0.01 |
Maternal smoking during pregnancy (%) | 9,357 (14.4) | 618 | 4,977 (22.0) | 393 | 0.09 |
Maternal education | 480 | 430 | 0.09 | ||
Junior high school (%) | 2,135 (3.3) | 1,422 (6.3) | |||
High school (%) | 47,166 (72.5) | 17,161 (76.0) | |||
University/graduate school (%) | 15,787 (24.3) | 3,986 (17.7) | |||
Family income | 4,251 | 2,131 | 0.07 | ||
Low (%) | 22,822 (37.2) | 9,385 (45.0) | |||
Middle (%) | 20,996 (34.2) | 6,521 (31.2) | |||
High (%) | 17,499 (28.5) | 4,962 (23.8) | |||
Early eczema (%) | 15,596 (24.2) | 1,169 | 5,282 (23.5) | 492 | 0.01 |
Older siblings (%) | 34,737 (53.2) | 245 | 13,175 (57.7) | 183 | 0.04 |
Formula consumption (%) | |||||
Very early (0–3 months old) | 30,540 (46.6) | 0 | 11,806 (52.0) | 315 | 0.05 |
Early (3–6 months old) | 26,567 (40.5) | 0 | 11,525 (50.1) | 0 | 0.08 |
Late (6–12 months old) | 28,331 (43.2) | 0 | 12,259 (53.3) | 0 | 0.09 |
Prevalence of food allergy (%) | |||||
At 6 months old | |||||
CMA | 150 (0.2) | 0 | 80 (0.3) | 0 | 0.01 |
At 12 months old | |||||
CMA | 682 (1.0) | 0 | 229 (1.0) | 4 | 0.00 |