STUDY EXERCISE
Each study participant was presented with 2 treatment scenarios (treatment A or treatment B), with a description of the features of each—defined as the likelihood of experiencing a migraine after the first day of treatment and the number of days with a migraine in the first month of treatment—and asked which they preferred. Based on responses, the probability of experiencing a migraine and number of days was varied.
Participants were randomized to which choice frame they were presented with first. Depending on the choice task, the subgroup population, and the participants’ answers, the choice task was repeated 2-6 times, each time changing the levels of performance of 1 attribute for 1 treatment. The changes were designed to move the participant toward being indifferent between the treatments and were made in accordance with predefined algorithms.
Exercise 1 varied the amount of reduction in the likelihood of migraine on day 1 with treatment B.
- If patients preferred treatment A, the likelihood of migraine after day 1 with treatment B was reduced in the next scenario.
- If they preferred treatment B, the likelihood of migraine after day 1 with treatment B was increased in the next scenario.
Exercise 2 varied the amount of reduction in the migraine days per month with treatment B.
- If they preferred treatment A, the number of migraine days per month with treatment B was reduced in the next scenario.
- If they preferred treatment B, the number of migraine days per month with treatment B was increased in the next scenario.
CHOICE FRAME 1
Treatment A
- Episodic migraine: Fixed reduction of 5 monthly migraine days, fixed 22% chance of migraine first day post dose
- Chronic migraine: Fixed reduction of 10 monthly migraine days, fixed 42% chance of migraine first day post dose
Treatment B
- Episodic migraine: Fixed reduction of 6 monthly migraine days, varied 0%-22% chance of migraine first day post dose
- Chronic migraine: Fixed reduction of 12 monthly migraine days, varied 10%-42% chance of migraine first day post dose
CHOICE FRAME 2
Treatment A
- Episodic migraine: Fixed reduction of 6 monthly migraine days, fixed 14% chance of migraine first day post dose
- Chronic migraine: Fixed reduction of 12 monthly migraine days, fixed 28% chance of migraine first day post dose
Treatment B
- Episodic migraine: Varied reduction of 0-6 monthly migraine days, fixed 22% chance of migraine first day post dose
- Chronic migraine: Varied reduction of 0-12 monthly migraine days, fixed 42% chance of migraine first day post dose