Migraine is the third most common medical condition and the eighth leading cause of disability worldwide, according to the World Health Organization; yet, migraines are still underdiagnosed and undertreated. The misdiagnosis of migraines is partly to blame for patients not receiving optimal care.
The US Headache Consortium recommends developing and validating cost-efficient screening tools. Identifying symptoms specific to migraines has been one of the bigger hurdles for developing migraine screening tools; in fact, nausea has largely been the only symptom used in studies to discriminate migraines from other headaches.
A. Brooke Walters, PhD, and Todd A. Smitherman, PhD, MS, of the Department of Psychology, University of Mississippi, Oxford, have developed and validated a new, 4-item migraine screening algorithm to help clinicians differentiate migraine headaches from nonmigraine headaches (Walters AB, Smitherman TA. Headache. 2016;56:86-94).
A total of 1829 young adults at a southeastern university completed a computer-administered Structured Diagnostic Interview for Headache. Based on their answers, participants were divided into 2 groups—the migraine group, comprised of those who met the 2013 International Classification of Headache Disorders, Third Edition (ICHD-3) criteria for episodic or chronic migraine, and the nonmigraine group, which included participants with headaches other than migraines.
The Structured Diagnostic Interview for Headache was slightly modified to align with the ICHD-3 criteria, and included questions related to ICHD-3 symptoms of migraines, headache frequency, disability, and other primary and secondary headache disorders.
Headache duration of 4 to 72 hours showed the highest sensitivity, followed by severity ≥5, photophobia, and phonophobia. Conversely, vomiting showed the highest specificity, followed by headache, duration of 4 to 72 hours, nausea, and headache-related disability.
Based on its specificity, sensitivity, and optimal operating point, the final migraine assessment model is called Migraine-4 and comprises 4 variables:
- Headache duration of 4 to 72 hours
This study is not the first to identify that nausea, phonophobia, and photophobia are the most effective symptoms for distinguishing migraines from other headaches. It is, however, the first study to develop a migraine model that includes these 4 variables, and to validate this as a functional migraine screening tool.
The Migraine-4 Screening Tool
Unlike previous studies that showed that disability was predictive of migraines, no such correlation was evident in this study; the investigators attributed this discrepancy to the variability in the way disability was defined in the different studies, ultimately concluding that the utility of this variable cannot be compared.
Conversely, the duration of headache was found to be an important diagnostic parameter of migraines in this study but not in other studies, possibly because this study did not categorize participants with probable migraines in the migraine group whereas other studies did. Individuals with probable migraines experience migraine attacks <4 hours in duration. In addition, the duration of headache is often not included in these types of studies as a potential diagnostic parameter, even though it is an important variable in the ICHD-3.
Overall, Migraine-4 has higher sensitivity and specificity values than other migraine screening tools, including ID Migraine and the Migraine Screen Questionnaire. The investigators underlined, however, that Migraine-4 is a screening tool only and should not be used alone to diagnose migraines.
“Because physicians often do not have time to assess all diagnostic criteria or conduct a lengthy structured interview, inclusion of this four-item measure in clinical settings could be used to identify migraineurs that so often go undiagnosed, so long as it performs well in future studies with clinical samples,” the researchers concluded.