An Observational Study of BOTOX® as Headache Prophylaxis for Chronic Migraine

The Baseline value included participants who had been admitted to the hospital for headache in the last 3 months prior to the baseline visit (first administration of BOTOX®); the Last Follow-up value included participants who been admitted to the hospital for headache since the previous visit.

The number of admission days is presented as the mean, normalized to a period of 90 days. The Baseline value included admissions during the last 3 months prior to the baseline visit (first administration of BOTOX®); the Last Follow-up value included admissions since the second-to-last visit.

The Baseline value included participants who had visited an HCP in the last 3 months prior to the baseline visit (first administration of Botox); the value for FU last included participants who visited an HCP since the second-to-last visit.

The MSQ is a 14-item questionnaire to measure health-related quality-of-life attributed to migraine in the past 4 weeks. Each item is scored on a 6-point scale where: 1=none of the time to 6=all of the time. There are 3 dimensions: Role-function Restrictive (questions 1 to 7; score range 7 to 42), Role-function Preventive (questions 8 to 11; score range 4 to 24) and Emotional-function (questions 12 to 14; score range 3 to 18). The individual dimension scores were converted to a score of 0 to 100; the total score ranged from 0 to 300 with higher numbers representing a better quality of life. A positive change from baseline in the dimension scores and the total score indicates that quality of life has improved.

The EQ-5D consists of 5 dimensions (mobility, self-care, usual activities, pain/discomfort, anxiety/depression) assessed by the participant using a 3-point scale: 1=no problems, 2=some problems and 3=extreme problems. The combination of levels from the 5 dimensions results in a health state code. The total score is calculated by converting the health state code into a score: start with score 1.000=[11111] (perfect health state), subtract 0.081 (constant) for any other state, subtract nothing for level 1 on any dimension, subtract appropriate level 2 or level 3 value for each dimension from a table of constants [Level 2: Mobility 0.069, Self-care 0.104, Usual activity 0.036, Pain/discomfort 0.123, Anxiety/depression 0.071] [Level 3: Mobility 0.314, Self-care 0.214, Usual activity 0.094, Pain/discomfort 0.386, Anxiety/depression 0.236], subtract 0.269 if any dimension has a level 3 problem. Higher numbers indicate better health. A positive change from Baseline indicates improvement.

The EQ-5D health state scale is a visual analog scale that ranges from 0 (worst imaginable health state) to 100 (best imaginable health state), with higher scores indicating a better state of health. Participants were asked to rate their health state on a drawn line that started at 0 and ended at 100. A positive change from baseline in the health state score indicates that the participant's health state has improved.

At each visit, participants were asked to provide the number of headache days he/she experienced in the last month. A headache day was defined as 4 or more hours of continuous headache. A negative change from Baseline (less headache days) indicates improvement.

At each visit, participants and physicians were asked to indicate the level of satisfaction that he/she had with the treatment. Physicians indicated the level of satisfaction with the patient's treatment. The 4- point scale consisted of the following responses: insufficient, moderate, good and very good. The combined percentage of "good" and "very good" responses by participants and physicians are reported.