Fig. 3

Change in monthly MSMD over DBTP and OLTP of the CM study in users of MSM at baseline. DBTP results are presented as adjusted means and 95 % CIs utilizing a generalized linear mixed model which includes treatment, visit, treatment by visit interaction, stratification factors region and medication overuse status, and baseline value as covariates and assuming a first-order autoregressive covariance structure. P-values for pairwise comparisons are nominal p-values without multiplicity adjustment. OLTP results are presented as mean ± SE. For patients switching from 70 mg to 140 mg between Weeks 4 and 28 of the OLTP, by Week 40 patients would have been on 140 mg for at least 12 weeks and would have therefore achieved steady state. Consequently, by Week 52, patients would have been on 140 mg for at least 24 weeks. DBTP, double-blind treatment phase; CI, confidence interval; CM, chronic migraine; M, month; MSM, migraine-specific medication; MSMD, migraine-specific medication days; OLTP, open-label treatment phase; SE, standard error