Measuring the impact of migraine for evaluating outcomes of preventive treatments for migraine headaches

Background: Migraine is characterized by headache with symptoms such as intense pain, nausea, vomiting, photophobia, and phonophobia that significantly impact individuals' lives. The objective of this study was to develop a strategy to measure outcomes from the patients' perspectives for use in evaluating preventive treatments for migraine. Methods: This study used a multi-stage process. The first stage included concept identification research through literature review, patient-reported outcome (PRO) instrument content review, and clinician interviews, and resulted in a list of concepts relevant to understand the migraine experience. These results informed the design of the subsequent concept elicitation stage that involved qualitative interviews of adults with migraine to understand their experiences. Information from these two stages was used to develop a conceptual disease model (CDM) of the migraine experience. This CDM was used to identify concepts of interest (COI) to evaluate patient-relevant outcomes for assessing treatment benefit of migraine prophylactics. In the final stage, existing PRO instruments were reviewed to assess coverage of concepts related to the selected COI. Results: Nine articles from 563 screened abstracts underwent full review to identify migraine-relevant concepts. This concept identification and subsequent concept elicitation interviews (N = 32; 21 episodic migraine; 11 chronic migraine) indicated that people with migraine experience difficulties during and between migraine attacks with considerable day-to-day variability in the impact on movement, ability to perform every day and social activities, and emotion. The CDM organized concepts as proximal to and more distal from disease-defining migraine symptoms, and was used to identify impact on physical function as the key COI. The item level review of PRO instruments revealed that none of the existing PRO instruments were suitable to collect data on impact of migraine on physical functioning, to evaluate treatment benefit. Conclusions: The impact of migraine includes impairments in functioning during and between migraine attacks that vary considerably on a daily basis. There is a need for novel PRO instruments that reflect patients' migraine experience to assess treatment benefit of migraine prophylactics. These instruments must evaluate the concepts identified and be able to capture the variability of patients' experience.