Table 1 Comparison of demographic and clinical characteristics between responders and non-responders from VPA arm

Sex

 F

14

77.8

21

80.8

0.8089

 M

4

22.2

5

19.2

Age class (years)

 18-34

2

11.1

3

11.5

0.8259

 35-44

9

50

11

42.3

 45-54

4

22.2

9

34.6

 55-64

3

16.7

3

11.5

BMI class

 (<18) underweight

0

0

1

3.9

0.4251

 (18–24.9) normal weight

8

44.4

16

61.5

 (25–29.9) overweight

8

44.4

6

23.1

 (>30) obese

2

11.2

3

11.5

Comorbidity

 No

17

94.4

20

76.9

0.1182

 Yes

1

5.6

6

23.1

Surgery

 No

2

11.8

6

24

0.3216

 Yes

15

88.2

19

76

 Missing

1

1

Headache days/months (V1)

 15-25

12

66.7

14

53.8

0.4405

 >25

6

33.3

12

46.2

Headache intensity (V1)

 Slight

0

0

1

3.8

0.6987

 Moderate

6

33.3

8

30.8

 Severe

12

66.7

17

65.4

Headache days/month (V2)

 15-25

17

94.4

19

73.1

0.1216

 >25

1

5.6

7

26.9

Headache intensity (V2)

 Slight

3

16.7

3

11.5

0.7040

 Moderate

11

61.1

19

73.1

 Severe

4

22.1

4

15.4

Headache duration (years)

 0-10

1

5.6

5

19.2

0.4249

 11-20

6

33.3

7

26.9

 21-30

7

38.9

6

23.1

 >30

4

22.2

8

30.7

 MOH duration (years)

 <1

2

11.1

4

15.4

0.5182

 1-3

4

22.2

6

23.1

 3-5

7

38.9

5

19.2

 >5

5

27.8

11

42.3

Overused drugs

 Analgesics >14d

9

50

6

23.1

0.2703

 Analgesics combinations >9d

2

11.1

3

11.5

 Drug combinations >9d

2

11.1

7

26.9

 Triptan combinations >9d

5

27.8

10

38.5