[Tools for assessing patient perception of the impact of migraine]

Patient-reported outcome, relating to the impact of disease and therapy on the wellbeing of the patient, has become an essential part of medicine, guiding enlightened public health policy and resource attribution. Assessment of patient-reported outcome requires the development of specific and validated instruments, generally questionnaires completed by the patient. In the case of migraine, a number of such specific instruments have been developed to measure severity, associated disability, effects on quality of life and overall impact of headache. In addition, generic quality of life measures have allowed migraine to be compared with other pathologies. For example, using the SF-36 generic health-related quality of life profile, quality of life has been shown to be negatively associated with headache severity, impacted more by migraine headaches than by other forms of episodic headache, and diminished to a similar degree in migraine and in other chronic disorders such as depression. Migraine-specific quality of life measures have also been developed, and these are more sensitive to change than generic measures. An example is the QVM scale that has been used to demonstrate an improvement in quality of life following treatment with a triptan. Moreover, quality of life scores on this measure are inversely related to the economic cost of migraine. Disability associated with migraine can be measured using the MIDAS scale. Disability has been shown to be determined by the frequency and severity of headaches and by the headache syndrome itself, with migraine causing more disability than other forms of episodic headache. The MIDAS scale has been used to develop treatment strategies stratified on the level of disability. The severity of individual headaches can be quantified using the MIGSEV scale. The severity of individual headaches has been shown to be closely associated with overall disability, quality of life and overall healthcare expenditure. Finally, the global impact of headaches is measured using the HIT-6 questionnaire, which discriminates well between different headache types and is again closely related to quality of life. These and other measures of the patient's perception of migraine have allowed an ever more precise picture of this multifacetted disorder to be drawn.