Table 2 Results of univariable and multivariable analysis for different risk factors

Age

< 0.0005

< 0.0005

   ≤ 31

1.00

1.00

   32 - 43

4.28

2.51-7.27

< 0.0005

4.44

2.48-7.94

< 0.0005

   44 - 54

5.96

3.49-10.19

< 0.0005

6.62

3.59-12.24

< 0.0005

   ≥ 55

2.98

1.75-5.09

< 0.0005

2.88

1.54-5.38

0.001

Female

1.77

1.23-2.56

0.002

1.69

1.09-2.61

0.018

Birth order

< 0.0005

0.001

   1

1.00

1.00

   2

1.17

0.78-1.73

0.481

0.93

0.59-1.47

0.760

   3

0.68

0.41-1.14

0.159

0.54

0.30-1.00

0.050

   ≥ 4

0.15

0.05-0.44

< 0.0005

0.08

0.02-0.30

< 0.0005

Day care age 0-3

0.50

0.35-0.73

< 0.0005

0.50

0.31-0.80

0.004

Residence age 0-6

0.011

0.015

   < 10000

1.00

1.00

   10000-100000

0.51

0.28-0.94

0.034

0.67

0.33-1.35

0.262

   > 100000

0.43

0.25-0.75

0.003

0.43

0.23-0.81

0.009