Fig. 4

Change in HIT-6™ Migraine Disability (ITT Population)^a. Abbreviations: HIT-6, 6-item Headache Impact Test; ITT, intention-to-treat; nVNS, non-invasive vagus nerve stimulation; SEM, standard error of the mean. ^aData are mean ± SEM; mean differences between treatment groups may not reflect calculated differences because of rounding; P values are from the t test; missing data were imputed using the last observation carried forward. ^bOne subject had missing HIT-6 data for both the baseline and nVNS periods