Validity of self‐reported migraine in adolescents and children.

Objective: To assess agreement for migraine day between self‐report and diagnostic guidelines for children and adolescents using a headache diary. Background: Trial guidelines recommend prospective collection of headache features and adoption of migraine day as an outcome measure, but there is no clear consensus on the definition of migraine day. Methods: This is a secondary analysis of data from two projects—a prospective cohort study validating a pediatric scale of treatment expectancy and a clinical trial of occipital nerve blocks to treat status migrainosus. Participants completed a text message‐based diary for 4 or 12 weeks (depending on treatment), and a detailed headache assessment on a random 20% of headache days. Using this assessment, we determined whether a headache day qualified for migraine or probable migraine, based on the International Classification of Headache Disorders, 3rd edition (ICHD‐3). Results: Of 122 enrolled children and adolescents, 106 (86.9%) completed ≥1 detailed headache assessment (438 entries). We found moderate agreement between self‐reported and ICHD‐derived migraine day, with a Cohen's Kappa of 0.50 (positive predictive value [PPV]: 0.66; negative predictive value [NPV]: 0.85; correlation: 0.51). Allowing for ICHD‐derived probable migraine significantly increased PPV (0.66 vs. 0.94; 95% CI: 0.57–0.74 vs. 0.90–0.97), but decreased NPV (0.85 vs. 0.293; CI: 0.77–0.90 vs. 0.199–0.40), Cohen's Kappa (0.50 vs. 0.237; CI: 0. 389–0.60 vs. 0.139–0.352), and correlation (r = 0.51 vs. 0.302; CI: 0.41–0.61 vs. 0.192–0.41). Pain severity (OR: 5.7; CI: 2.39–13.8), photophobia (OR: 4.1; CI: 1.02–16.6), and phonophobia (OR: 7.5; CI: 1.95–29.3) were significantly associated with participants' perception of migraine. Conclusion: We found only moderate agreement between self‐reported and ICHD‐derived migraine day, suggesting both measures are not equal but may represent overlapping aspects of migraine as a disease. This highlights the difficulty of applying ICHD criteria to individual attacks. We recommend greater methodological transparency in future research to avoid readers conflating both measures. [ABSTRACT FROM AUTHOR]