The 15‐day threshold in the definition of chronic migraine is reasonable and sufficient—Five reasons for not changing the ICHD‐3 definition

might be withheld from them because these medications are not approved for episodic migraine (such as botulinumtoxin and the same for calcitonin gene- related peptide antibodies in some coun -tries). Changing ICHD criteria might seem like a viable solution for this problem. When looking at the consequences for the use of already Food and Drug Administration– approved treatments one, however, must be very careful. If a clinical trial has applied the current ICHD criteria for episodic and CM, a benefit for the group of CM patients means that there is a benefit for patients with 15 or more headache days per month and not for those with less, regardless of what we call the subtype of migraine. 19 Should we choose to change the nomenclature and call migraine with eight or more headache days chronic, that still does not alter the sci entific evidence that the clinical efficacy has been established in patients with ≥15 headache days. Indication for a specific medica tion can only be broadened if new evidence may suggest efficacy in another subgroup of patients. For example, a recent open- label study suggests probable efficacy of onabotulinumtoxinA in pa tients with HFEM, 20 which itself needs to be confirmed in a proper randomized controlled trial. When treating patients with severe pain conditions one is often faced with a lot of despair and those in despair will clutch at a straw. As responsible physicians, our ac tions must be evidence based. Consequently, we must not subject patients to treatments that have not been shown to be effective in their condition regardless of what the condition is called. We do appreciate the call to broaden the indication of certain medi cations to a higher number of patients. The solution is however not to simply include HFEM into CM, but to do proper studies in HFEM patients with medications that have proven efficacy in CM.