Table 5 Number of patients with favorable (reduction in headache frequency >  50%) and unfavorable (< 50%) outcomes after 3 months of treatment. The odds ratio was computed for a single drug compared with the remaining population

< 50%

28

98

288

40

196

27

> 50%

17

67

137

24

80

9

45

165

425

64

276

36

Odds ratio

1.23

1.48

0.93

1.23

0.77

0.66

95% CI

0.67 to 2.30

1.05 to 2.08

0.71 to 1.2

0.71 to 2.08

0.57 to 1.046

0.3 to 1.4

z statistic

0.69

2.25

0.461

0.78

1.67

1.037

Sig. level

P = 0.48

P = 0.02

P = 0.64

P = 0.43

P = 0.09

P = 0.29