Page 80 - The clinical aspects and management of chronic migraine Judith Anne Pijpers

Chapter 4
Figure 4: Change from baseline of the 4-weekly number of days with headache (A) and migraine (B) over 48 weeks.
To compare the long-term effects of withdrawal plus BTA versus withdrawal plus placebo, the open label phase and follow-up phase were included in the analysis. As some placebo-treated patients received BTA in the open label phase, including the outcomes of these patients in the analysis of ‘placebo-treated patients’ would potentially influence the comparison. To avoid this, the open-label results (i.e. outcomes after 24, 36 and 48 weeks) of placebo-treated participants receiving open-label BTA were set to missing. In this way, participants treated only with placebo were compared to participants who had received one or two cycles of BTA.
Depicted are adjusted means with 95% CI; headache and migraine days at baseline are derived from the model. A headache day is a day with a migraine or non-migraine headache of any duration; A migraine day is a day with headache fulfilling migraine criteria or treated with acute anti-migraine medication.
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