Fig. 1

Mean (SD) change from baseline in frequency of headache days. Mean (SD) change from baseline in frequency of headache days. Patient-reported estimated number of days per month with a headache (≥ 4 h) at each administration visit 1 through 8. Patients treated with (a) 155 U onabotulinumtoxinA or (b) 156 U – 195 U at 4 or more visits. * p < 0.001 paired t- test for change vs baseline. h, hours; SD, standard deviation; U, units