Migraine heterogeneity. Disability, pain intensity, and attack frequency and duration.

Data from population-based studies are summarized to characterize the full range and variability of the impact migraine has on the individual. Despite differences in methods and data collection in population-based studies describing disability, pain intensity, and attack frequency as well as the duration of migraine and other headaches, several patterns emerge. On average, migraine headaches are more disabling, more painful, and longer in duration than other types of headaches. Females report more pain and disability with headache than do males. Although disability measurements are important in demonstrating the effect of headache on both the individual and society, actual measurements often fall short. Most studies use only workdays lost as the sole measure of disability. Most migraineurs do not miss work while experiencing a headache; instead, they attempt to function on the job, with considerably reduced effectiveness. Computing only workdays lost does not account for impairment at work nor does it show the impact of migraine on other aspects of life. In addition, evidence suggests the presence of a pain intensity threshold for disability. Headache-related pain intensity below the threshold is not associated with disability. Despite the threshold of pain intensity for disability, a significant proportion of migraine sufferers report levels of pain intensity above the threshold in the absence of work-related disability. The grading of headache severity should be a composite that would permit a more complete image of the heterogeneity of migraine's effects and a more accurate idea of the need for healthcare services. This composite should include two areas: (1) more complete measures of life impact, encompassing daily activities in a number of domains, including work, family, and social activities; and (2) an assessment of pain intensity and attack frequency.