Single Centered Diary-based Study to Identify Course and Characteristics of Hormone Withdrawal Headaches/Migraines in Users of Combined Hormonal Contraceptives

Participant recruitment is performed through advertisement placed in University Zürich (USZ) online. Advertisement in offices of neurologists and headache specialists, homepage of the Swiss headache society.

Interested women contact the investigators via email and are called back by one of the study doctors or students within 1 day from Monday-Friday. This phone call is thought to inform the women about the study in more detail and for the investigators to check eligibility. During this call the participants are informed about the study procedure and can ask any question. Here most important points are use of a CHC in a 21/7 regimen, regular (at least once on two months) withdrawal migraine/headaches, intention to continue the use of the contraceptive for 3 more months.

If the participants decide to participate, inclusion and exclusion criteria are checked. If women are applicable they receive the consent form and the study information with an envelope for return. If more questions come up the investigators are available per email and phone for answers. If a patient doesn't return the consent form the investigator will delete the personal data, which collected before. Only the year of birth will be noted in the personal data.

After consent participants receive headaches diaries (with mail /post) and a prepaid envelope (for return). Participants are also offered the option to return their diaries electronically via email to the study doctor. Furthermore participants receive in a second phone contact instructions, how to fill in the headache diary and the day of study start (first day of the next pill package).

Headache diaries should be returned monthly (per email or post) and are conducted for 3 pill cycles.