Migraine-Related Disability According to Headache Frequency Subclassifications: A Systematic Review and Meta-Analysis

BackgroundThis systematic review and meta-analysis synthesized migraine-related disability outcomes according to headache frequency subclassifications, including low-frequency episodic migraine (LFEM), high-frequency episodic migraine (HFEM) and chronic migraine (CM).MethodsWe searched the PubMed and Cochrane Library (CENTRAL) up to 16 October 2024 for peer-reviewed non-interventional studies reporting migraine-related disability outcomes in CM and subclassifications of episodic migraine (e.g. LFEM and HFEM). Eligible studies with an HFEM subgroup were grouped by headache frequency measure (monthly migraine days [MMD] or monthly headache days [MHD]), HFEM subgroup, disability parameter and study setting. Random-effects meta-analyses were conducted on groups with three or more studies, with the results presented in forest plots. Risk of bias was assessed using Joanna Briggs Institute tools.ResultsOf the 32 included studies, 27 were grouped, yielding five meta-analysis groups containing three or more studies. All five groups had an HFEM subgroup of 8-14 MHD. Accordingly, we classified LFEM as 0-7 MHD and CM as ≥15 MHD. Ten studies contributed data to the five meta-analysis groups. Estimated pooled values are reported by headache frequency subgroup for each meta-analysis group: LFEM (95% confidence interval [CI]), HFEM (95% CI) and CM (95% CI). For meta-analysis group 1, four population-based studies reported Migraine Disability Assessment (MIDAS) Grade IV proportions, with pooled values of 11.1% (7.1-17.1), 43.9% (31.8-56.9) and 57.5% (42.7-71.1), respectively. For meta-analysis group 2, five population-based studies documented Work Productivity and Activity Impairment (WPAI) outcomes. Pooled mean overall work productivity impairment (OWPI) scores were 36.9% (30.8-43.1), 44.7% (38.4-51.0) and 52.0% (47.7-56.3), respectively. Pooled mean activity impairment (AI) scores were 36.4% (33.7-39.1), 46.4% (42.8-50.0) and 53.5% (52.1-54.8), respectively. For meta-analysis group 3, three clinic-based studies presented MIDAS Grade IV proportions. Pooled values were 15.0% (4.4-40.5), 42.4% (17.1-72.4) and 65.7% (30.3-89.4), respectively. For meta-analysis group 4, three clinic-based studies reported WPAI outcomes. Pooled mean OWPI scores were 28.8% (21.6-35.9), 40.2% (36.2-44.2) and 49.6% (46.3-52.9), respectively. Pooled mean AI scores were 29.4% (21.9-36.9), 43.5% (39.0-48.1) and 51.6% (48.8-54.4), respectively. For meta-analysis group 5, three clinic-based studies detailed MIDAS scores. Pooled mean scores were 10.7 (3.9-17.5), 23.9 (9.4-38.4) and 49.6 (15.8-83.3), respectively.ConclusionsThis study showed a pattern of increasing migraine-related disability with rising headache frequency. Regardless of study setting, our meta-analyses also suggested a severe level of disability in many individuals (42%-44%) with HFEM, highlighting an unmet need for more effective migraine management. Disability burden and headache frequency should both be considered when determining treatment needs and therapy access, particularly for patients with HFEM.Study Registration: INPLASY2024120039.