Fig. 1

Preventive medication according to the German guideline for migraine [8]. ^aPreventive medication(s) with good evidence. ^bOff-label, but may be prescribed at the expense of the German Health Care System (Social Health Insurance) pursuant to Annex VI, Section K of the German medicinal product directive. ^cPreventive medication with lower evidence. In the current analyses, Group 1 preventive medications are in-label preventive medications plus valproic acid; Group 2 preventive medications are all preventive treatments according to the German guideline for migraine (in- and off-label). ACEi angiotensin-converting enzyme inhibitor; ARA angiotensin II receptor antagonist