Fig. 4

Patient Global Impression of Change (A) and patient-identified most bothersome symptom (B) scores (FAS). The model includes the following fixed effects: visit, region, stratification factor (monthly headache days at baseline: < 20/ ≥ 20), and treatment as factors, treatment-by-visit interaction, and stratum-by-visit interaction. The PGIC and the PI-MBS are ranked on a scale of 1–7, and the lower the score the higher the clinical improvement. Patients could rate their change on the PGIC and PI-MBS scale as “Very much improved”, “much improved”, “minimally improved”, “no change”, “minimally worse”, “much worse”, or “very much worse”. Data represent mean ± standard error. FAS, full analysis set; PGIC, Patient Global Impression of Change; PI-MBS, patient-identified most bothersome symptom