Interictal burden in migraine: a systematic review of conceptual domains and measurement properties of instruments.

Migraine significantly affects individuals during acute attacks and headache-free periods. This research evaluates tools measuring the interictal burden of migraines. Patient-reported outcome measures (PROMs) assess this burden, but their measurement quality remains unclear. A systematic search of multiple databases identified 29 studies for evaluation. The COSMIN methodology assessed the measurement properties of these tools. Three main instruments were identified: the Migraine Interictal Burden Scale-4, the Eurolight questionnaire, and the Fear of Attacks Inventory. Seven interictal burden domains emerged: functional impairment, social impact, emotional distress, cognitive dysfunction, sensory symptoms, physical symptoms, and behavioral changes. Findings focused on construct validity and responsiveness. The MIBS-4 showed strong validity and sensitivity to change with treatments. However, more comprehensive studies are necessary to improve the quality of these assessments. Addressing these gaps can enhance our understanding of migraine's hidden impact on patients' lives. Clinical relevance: This research highlights the need for better tools to assess migraine's interictal burden, ultimately improving patient care and treatment strategies.