Characterizing gaps in the preventive pharmacologic treatment of migraine: Multi-country results from the CaMEO-I study.

Objective: To analyze data from the Chronic Migraine Epidemiology and Outcomes-International (CaMEO-I) Study in order to characterize preventive medication use and identify preventive usage gaps among people with migraine across multiple countries.

Background: Guidelines for the preventive treatment of migraine are available from scientific organizations in various countries. Although these guidelines differ among countries, eligibility for preventive treatment is generally based on monthly headache day (MHD) frequency and associated disability. The overwhelming majority of people with migraine who are eligible for preventive treatment do not receive it.

Methods: The CaMEO-I Study was a cross-sectional, observational, web-based panel survey study performed in six countries: Canada, France, Germany, Japan, the United Kingdom, and the United States. People were invited to complete an online survey in their national language(s) to identify those with migraine according to modified International Classification of Headache Disorders, 3rd edition, criteria. People classified with migraine answered questions about current and ever use of both acute and preventive treatments for migraine. Available preventive medications for migraine differed by country. MHD frequency and associated disability data were collected. The American Headache Society (AHS) 2021 Consensus Statement algorithm was used to determine candidacy for preventive treatment (i.e., ≥3 monthly MHDs with severe disability, ≥4 MHDs with some disability, or ≥6 MHDs regardless of level of disability).

Results: Among 90,613 valid completers of the screening survey, 14,492 met criteria for migraine and completed the full survey, with approximately 2400 respondents from each country. Based on the AHS consensus statement preventive treatment candidacy algorithm, averaging across countries, 36.2% (5246/14,492) of respondents with migraine qualified for preventive treatment. Most respondents (84.5% [4431/5246]) who met criteria for preventive treatment according to the AHS consensus statement were not using a preventive medication at the time of the survey. Moreover, 19.3% (2799/14,492) of respondents had ever used preventive medication (ever users); 58.1% (1625/2799) of respondents who reported ever using a preventive medication for migraine were still taking it. Of the respondents who were currently using a preventive medication, 50.2% (815/1625) still met the criteria for needing preventive treatment based on the AHS consensus statement.

Conclusions: Most people with migraine who qualify for preventive treatment are not currently taking it. Additionally, many people currently taking preventive pharmacologic treatment still meet the algorithm criteria for needing preventive treatment, suggesting inadequate benefit from their current regimen.