Table 1 Patients’ characteristics and wheezing episode

Age at recruitment (mean ± SD)

1.32 ± 0.62

2.61 ± 1.44

4.57 ± 0.79

–

–

Age at follow-up (mean ± SD)

4.95 ± 0.70

6.28 ± 1.26

8.19 ± 0.75

–

–

Gender [n (%)]

0.62

0.734

 Male

11 (78.6)

43 (79.6)

12 (70.6)

 Female

3 (21.4)

11 (20.4)

5 (29.4)

Birth history [n (%)]^a

3.60

0.134

 Full-term

11 (78.6)

47 (87.0)

17 (100.0)

 Preterm

3 (21.4)

7 (13.0)

0 (0.0)

Recruitment season [n (%)]^a

1.24

0.891

 Spring

9 (64.3)

26 (48.1)

8 (47.1)

 Autumn

3 (21.4)

16 (29.6)

5 (29.4)

 Winter

2 (14.3)

12 (22.2)

4 (23.5)

Siblings [n (%)]^a

 No-siblings

8 (57.1)

37 (68.5)

14 (82.4)

2.32

0.321

Breastfed history [n (%)]^a

 Yes

14 (100.0)

50 (92.6)

15 (88.2)

1.39

0.496

Childcare [n (%)]^a

 Yes

0 (0.0)

1 (1.9)

1 (5.9)

1.54

0.605

Pets kept when the child was born [n (%)]^a

 Yes

2 (14.3)

8 (14.8)

2 (11.8)

0.17

1.000

Current pet ownership [n (%)]^a

 Yes

2 (14.3)

6 (11.1)

2 (11.8)

0.40

0.892

Mother smoking history [n (%)]^a

 Yes

1 (7.1)

1 (1.9)

1 (5.9)

2.14

0.300

Other family member smoking history [n (%)]^a

 Yes

9 (64.3)

31 (57.4)

10 (58.8)

0.25

0.949

Onset age of wheezing (months)^b

6.0 (5.8, 12.0)

12.0 (6.0, 24.0)

36.0 (36.0, 48.0)

43.66

< 0.001

Current wheezing episode at recruitment^b

4 (3, 4)

4 (3, 5)

4 (2, 6)

0.16

0.925

Current wheezing episode at follow-up^b

0 (0, 0)^c

0 (0, 1)

0 (0, 1)

0.98

0.323