Headache-related health resource utilisation in chronic and episodic migraine across six countries
Joanna C Sanderson, Emily B Devine, Richard B Lipton, Lisa M Bloudek, Sepideh F Varon, Andrew M Blumenfeld, Peter J Goadsby, Dawn C Buse, Sean D Sullivan
Journal of Neurology, Neurosurgery & Psychiatry Dec 2013, 84 (12) 1309-1317; DOI: 10.1136/jnnp-2013-305197