The three dimensions of headache impact: pain, disability and affective distress

It is increasingly recognized that pain measures alone provide incomplete i nformation about the impact of pain on functioning or quality-of-life. A wi de range of measures that promise to provide additional information about t he impact of pain on people's lives are thus coming into use. In order to c larify the construct of headache impact, we attempted to identify the dimen sions assessed by a set of 22 headache-impact measures and to identify the specific measures that best assessed each of these headache-impact dimensio ns. Adults (n = 329) with frequent benign headache disorders completed a co mprehensive assessment battery that included 22 headache-impact measures. F actor analysis was then used to identify dimensions underlying the headache -impact measures. Three factors labeled Affective Distress, Pain Density an d Disability best accounted for correlations among headache-impact measures . Interfactor correlations ranged between 0.37 and 0.20, suggesting three c orrelated but separable impact dimensions. These results suggest the constr uct of headache impact needs to be broadened beyond pain and disability to include affective distress. An adequate assessment of the impact of recurre nt headache disorders in clinical trials and other research may require mea sures from all three of the headache-impact dimensions identified here. (C) 1999 International Association for the Study of Pain. Published by Elsevie r Science B.V.