Table 1 Baseline demographic and clinical characteristics

Number of participants

4

4

4

 Males

1

1

2

 Females

3

3

2

Age ± SD (range)

36.0 ± 12.8 (26–54)

49.8 ± 12.3 (32–58)

48.0 ± 9.8 (39–61)

Duration (years with headache ± SD)

7.3 ± 3.3

8.5 ± 1.3

13.8 ± 10.4

Headache frequency (mean 30 days/month)

20.5 ± 9.9

25.5 ± 5.2

19.3 ± 7.9

Headache duration (mean hours/day)

19.5 ± 3.8

19.5 ± 7.7

19.3 ± 5.1

Headache intensity (mean 0–10 VAS)

6.0 ± 2.3

6.0 ± 0.7

7.0 ± 2.0

Co-morbid migraine

0/4

2/4

0/4

Primary end-point (1 month baseline)

 Headache frequency (mean 30 days/month)

20.0 ± 12.0

22.8 ± 12.3

19.0 ± 8.4

Secondary end-points (1 month baseline)

 Headache duration (mean hours/day)

9.6 ± 5.2

10.9 ± 3.3

9.9 ± 6.9

 Headache intensity (mean 0–10 VAS)

6.6 ± 2.5

4.3 ± 1.7

6.3 ± 1.6

 Headache index (HI)

(mean frequency × duration × intensity)

956

95% CI 438 to 1475

1141

95% CI 283 to 1999

1635

95% CI −37 to 3307