Table 1.
Maternal and child characteristics
| |
n = 4,634 |
|
|---|---|---|
| Observed | After multiple imputations | |
|
Maternal characteristics |
|
|
| Age (years)* |
31.1 (4.9) |
31.1 (4.9) |
| Highest completed education (%) |
|
|
| Non-completed, primary or secondary |
47.1 (2,050) |
48.2 (2,234) |
| Higher |
52.9 (2,299) |
51.8 (2,400) |
| Missing |
6.2 (285) |
- |
| Parity (%) |
|
|
| Nulliparity |
61.6 (2,762) |
61.4 (2,844) |
| Multiparity |
38.4 (1,722) |
38.6 (1,790) |
| Missing |
3.2 (150) |
- |
| History of asthma or atopy (%) |
|
|
| No |
61.9 (2,369) |
59.0 (3,734) |
| Yes |
38.1 (1,460) |
41.0 (1,900) |
| Missing |
17.4 (805) |
- |
|
Fetal and Child characteristics |
|
|
| Male sex (%) |
49.9 (2,313) |
49.9 (2,313) |
| Gestational age at birth (weeks)$ |
39.9 (37.0-42.1) |
39.9 (37.0-42.1) |
| Birth weight (grams)* |
3,439 (556) |
3,439 (556) |
| Ethnicity (%) |
|
|
| European |
70.4 (3,144) |
69.9 (3,240) |
| Non-European |
29.6 (1,320) |
30.1 (1,394) |
| Missing |
3.7 (170) |
- |
| Breastfed (%) |
|
|
| No |
7.7 (339) |
8.0 (371) |
| Yes |
92.3 (4,089) |
92.0 (4,263) |
| Missing |
4.4 (206) |
- |
| Day care attendance (%) |
|
|
| No |
48.0 (1,894) |
50.0 (2,316) |
| Yes |
52.0 (2,050) |
50.0 (2,318) |
| Missing |
14.9 (690) |
- |
| Pet keeping (%) |
|
|
| No |
65.5 (2,399) |
64.6 (2,993) |
| Yes |
34.5 (1,263) |
35.4 (1,641) |
| Missing |
21.0 (972) |
- |
| Lower respiratory tract infections age 1 year (%) |
|
|
| No |
86.4 (3,165) |
85.4 (3,957) |
| Yes |
13.6 (498) |
14.6 (677) |
| Missing |
21.0 (971) |
- |
| Lower respiratory tract infections age 2 years (%) |
|
|
| No |
87.9 (3,494) |
87.4 (4,052) |
| Yes |
12.1 (484) |
12.6 (582) |
| Missing |
14.2 (659) |
- |
| Lower respiratory tract infections age 3 years (%) |
|
|
| No |
93.3 (3,453) |
92.7 (4,294) |
| Yes |
6.7 (247) |
7.3 (340) |
| Missing |
20.2 (934) |
- |
| Smoking of father (%) |
|
|
| No |
57.4 (2,153) |
57.4 (2,658) |
| Yes |
42.6 (1,599) |
42.6 (1,976) |
| Missing |
19.0 (882) |
- |
| Fetal smoke exposure (%) |
|
|
| No |
86.9 (3,246) |
86.4 (4003) |
| Yes |
13.1 (489) |
13.6 (631) |
| Missing |
19.4 (899) |
- |
| Infant smoke exposure (%) |
|
|
| No |
82.3 (3,391) |
81.4 (3,770) |
| Yes |
17.7 (728) |
18.6 (864) |
| Missing |
11.1 (515) |
- |
| Wheezing age 1 year (%) |
|
|
| No |
74.0 (2,922) |
74.1 (3,433) |
| Yes |
26.0 (1,028) |
25.9 (1,201) |
| Missing |
14.8 (684) |
- |
| Wheezing age 2 years (%) |
|
|
| No |
82.1 (3,358) |
82.6 (3,827) |
| Yes |
17.9 (731) |
17.4 (807) |
| Missing |
11.8 (545) |
- |
| Wheezing age 3 years (%) |
|
|
| No |
89.0 (3,417) |
89.4 (4,143) |
| Yes |
11.0 (421) |
10.6 (491) |
| Missing | 17.2 (796) | - |
Values are percentages (absolute values), means (SD)* or medians (5-95th percentile)$.
Missing percentages are given for the total population of analysis n = 4634. Other percentages are valid percentages.