Briefly, adults aged 18 to 70 with a history of migraine (according to the International Classification of Headache Disorders, third edition [ICHD-3] beta criteria [17]) for ≥12 months prior to screening and prospectively confirmed CM (headache on ≥15 days and ≥8 days fulfilling ICHD-3 beta criteria for migraine, probable migraine, or use of triptan or ergot medications) during the 28-day pretreatment baseline period were eligible to participate [16]. Patients who used opioids (including codeine) or barbiturates on >4 days per month were excluded from the trial. Additional inclusion and exclusion criteria are provided in a Table in Additional file 1.