Fig. 1From: Effects of onabotulinumtoxinA treatment in chronic migraine patients with and without daily headache at baseline: results from the COMPEL StudyOnabotulinumtoxinA effect on (a) headache-day frequency and (b) moderate to severe headache-day frequency. *P < 0.001 for within-treatment-group comparison from baseline. P values shown in the figure are between-subgroup differences in change from baseline; data are observed dataBack to article page