Using a headache duration of 30 or more minutes, rather than 4 or more hours, resulted in a 5.4% increase in monthly migraine days.

“Having a standardized definition for a migraine day is critical for ensuring consistency and comparability across research studies and clinical practice,” Britt van der Arend, PhD-candidate, and Gisela M. Terwindt, MD, PhD, explain. “Without a standardized definition, studies may use varying definitions of a migraine day, which can lead to confusion and inconsistency when comparing study results. Furthermore, lack of clarity in defining days with migraine can also make it difficult to establish clinical guidelines and recommendations for the management of migraine.”

For a study published in Cephalalgia, van der Arend, Dr. Terwindt, and colleagues retrospectively compared different definitions of a migraine day, using headache e-diary entries from 1,494 adults. They employed a baseline migraine definition according to one of the following: migraine characteristics with a duration of ≥4 hours; triptan use, regardless of its effect; or visual aura that lasted between 5 and 60 minutes.

“Importantly, we studied the effect of adjusting the headache duration from 4 or more hours to 30 minutes or more and evaluated the effect of including days with effective triptan response versus all days with triptan intake,” van der Arend says. “This is important, as most patients are told by their treating physician not to wait for 4 hours before trying to end an attack.”

Use of 30-Minute Duration Increases Monthly Migraine Days

For migraine days characterized by triptan intake only, 66.2% lasted for less than 4 hours, according to the study results. Changing the headache duration criteria to include migraine lasting for 30 or more minutes resulted in a decline in days characterized by triptan intake only and a 5.4% increase in total migraine days. The additional migraine days lasted for a median duration of 2.5 hours.

“The headache duration was indeed the most important missing criterion in migraine days based on triptan intake,” Dr. Terwindt explains. “This is likely explained by the effectiveness of the triptan. Using a headache duration of 30 or more minutes resolved this issue and resulted in a 5.4% increase in monthly migraine days in which a triptan was not used. Although the duration is shorter, most migraine days identified by the adjusted duration criterion still lasted for more than 2 hours.”

Aside from the duration, the migraine days identified by the adjusted criteria—30 or more minutes rather than 4 or more hours—fulfill the other characteristics of a migraine, the researchers note. “Therefore, we believe that these migraine days are still significant and should be included in the calculation of monthly migraine days,” van der Arend says (Figure).

Incorporating the New Duration into Practice & Research

The researchers suggest that the duration criteria of 30 or more minutes, rather than 4 or more hours, should be used, because all other migraine characteristics—such as pulsating, moderate or severe pain, nausea and/or vomiting, and photophobia and phonophobia, among others—were still met by patients with a migraine duration of 30 or more minutes.

“Since clinicians recommend that patients take acute medication at the start of the migraine headache phase, it would be wrong not to define an aborted attack as a migraine day,” van der Arend notes. “Defining too few migraine days should be avoided, as it can cause an underestimation of the actual burden, due to patients following advice not to delay the use of acute medication, for example.”

It is also hoped that this definition will be used in new clinical research, including in studies of acute and preventive migraine treatments and in comparisons of new treatments with real-world data.

“This recommended new definition of migraine day duration is extremely important for algorithms on which e-headache diaries are based for clinical purposes,” Dr. Terwindt says. “If we aim to incorporate e-tools in the future, we need to show that these tools accurately measure what we aim to measure.”