Funding for this research was provided by:
Received: 7 February 2019
Accepted: 13 May 2019
First Online: 31 May 2019
Ethics approval and consent to participate
: Ethical approval for the study was obtained by the Regional Ethical Board in Lund in 2018 (Dnr 2018/347). Informed consent was obtained from all patients included in the study.
: Only deidentified data was available for analyses and the results are only presented on an aggregated level. Ethical approval for the study was obtained and each participating person signed an informed consent before participating.
: FH, SO and UP have no competing interests.ML is director of Tjörn Headache Clinic in Sweden.
: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.