The essential words here are "best possible". There has been no agreement on the meaning of "best" in this context. Consequently, there is no established methodology for evaluating headache services or agreed standard against which to evaluate them.

So here the key questions are:

• How is "quality" defined in the context of headache services, and from whose perspective(s); and
• In the light of a definition of quality, how, methodologically, should headache services be evaluated?

The Global Campaign, through a worldwide process of consultation, has proposed answers to these questions, developing both a definition of "quality" and a set of quality indicators coupled with methods to apply them. These are being empirically validated in various countries.

Collaborators:

• SW Broner, The Headache Institute, Columbia Presbyterian Hospital, New York, NY, USA
• C Gaul, University of Duisburg-Essen, Essen, Germany
• R Gil-Gouveia, Hospital da Luz, Lisboa, Portugal
• C Jenkinson, University of Oxford, Oxford, UK
• R Jensen, Danish Headache Centre, Glostrup Hospital, Glostrup, Denmark
• Z Katsarawa, University of Duisburg-Essen, Essen, Germany
• EW Loder, Brigham and Women's / Faulkner Hospitals, Boston, MA, USA
• S Perera, Ministry of Health Care & Nutrition, Colombo, Sri Lanka
• M Peters, University of Oxford, Oxford, UK