“…Future studies should apply more than one measure of headache related disability, distress, or respectively quality of life (Walker and Green, 1991;Eccleston et al, 2005;Tkachuk et al, 2003;Merlijn et al, 2006) in order to explore the underlying constructs and their associations more closely. A comparison of their response characteristics, psychometric standards, predictive capacity for measures of health behaviour and sensitivity to change after interventions would give better grounds for deciding on their usefulness.…”