Table 5 Multivariate analysis of risk factors for headache

Age (year)

 20–29

1.00

Referent

1.00

Referent

 30–39

0.63

0.39–1.01

0.63

0.39–1.01

 40–49

0.42

0.26–0.67

0.42

0.26–0.67

 50–59

0.31

0.19–0.49

0.31

0.19–0.49

 60–69

0.19

0.10–0.35

0.19

0.10–0.35

 70–79

0.36

0.08–1.60

0.36

0.08–1.60

P < 0.0001

P < 0.0001

Stress

 Very high

3.71

1.28–10.77

1.75

0.94–3.25

 Somewhat high

2.41

0.86–6.72

2.23

1.24–4.03

 Average

1.70

0.62–4.68

1.66

0.93–2.97

 Low

1.81

0.62–5.34

1.42

0.75–2.69

 Little or none

1.00

Referent

1.00

Referent

P = 0.0010

P = 0.0003

Number of other poor health conditions

 0

1.00

Referent

1.00

Referent

 1

3.32

2.27–4.86

2.74

2.19–3.43

 2

4.23

2.83–6.32

3.85

3.03–4.88

 3

4.07

2.53–6.54

4.50

3.47–5.82

 4–5

7.82

5.00–12.24

7.87

6.11–10.14

 6 or more

17.68

10.66–29.34

15.78

11.75–21.18

P < 0.0001

P < 0.0001

Alcohol drinking

 Non-drinker

1.00

Referent

1.00

Referent

 Less than 1 unit/day

0.80

0.60–1.08

0.79

0.67–0.93

 1 to less than 2 units/day

0.61

0.43–0.87

0.69

0.53–0.91

 2 to less than 3 units/day

0.59

0.39–0.91

0.37

0.20–0.68

 3 units/day or more

0.40

0.25–0.63

0.50

0.26–0.96

P = 0.0004

P < 0.0001