Efficacy and Safety Study of BOTOX® Compared to Topiramate for the Prevention of Chronic Migraine in Adults

Change From Baseline in the Frequency of Headache Days Per 28-day Period

Participants recorded their headaches in a daily e-diary. A headache day was defined as a calendar day (00:00 to 23:59) with 4 or more hours of headache and/or headache of any duration with the use of migraine-specific acute headache medication(s). The number of headache days over the 28-day period was counted. A negative change from Baseline (less headache days) indicates improvement.

Time frame: Baseline (First 28 days from Screening) to the last 28-day period ending with Week 32

Change From Baseline in Headache Impact Test (HIT-6) Total Score

The HIT-6 is a valid disease-targeted measure used to assess the impact of headaches, comprised of 6 items that assess pain, role functioning, social functioning, cognitive functioning, vitality, and psychological distress. A total score is created by summingacross all items, and ranges from 36 (no impact) to 78 (severe impact) reflecting a "best to worst" scoring. A negative change from Baseline (a lower score) indicates improvement.

Time frame: Baseline (Day 1) to the last 28-day period ending with Week 30

Percentage of Participants With a ≥ 70% Decrease From Baseline in the Frequency of Headache Days

Participants recorded their headaches in a daily e-diary. A headache day was defined as a calendar day (00:00 to 23:59) with 4 or more hours of headache and/or headache of any duration with the use of migraine-specific acute headache medication(s). The number of headache days over the 28-day period was counted. The percentage of participants with a ≥ 70% decrease in headache days in the 28-day period prior to Week 32 relative to Baseline (28-day period prior to Day 1) is reported.