CaMEO Study Shows Low Global Usage Rates of Preventives for Migraine and Inconsistencies With 2021 AHS Consensus Statement Algorithm

Dawn Buse, PhD

Recently published data from CaMEO-I, a cross-sectional, multinational, web-based panel survey study, showed that around one-third of patients with migraine qualified for preventive treatment, and among those who did qualify, 84.5% were not currently taking it. In addition, among those who were currently using a preventive medication for migraine, only half still met the study criteria for preventive treatment, suggesting that they were not experiencing adequate clinical benefit based on the 2021 American Headache Society (AHS) Consensus Statement algorithm.

The study, performed across Canada, France, Germany, Japan, the United Kingdom, and the United States, included 90,613 valid completers of a screening survey, of which 14,492 met criteria for migraine and completed the survey. Led by Dawn Buse, PhD, a clinical professor of neurology at the Albert Einstein College of Medicine, the study used the AHS 2021 Consensus Statement algorithm to determine candidacy for preventive treatment.

Buse et al wrote, "As the criteria to be offered preventive treatment allowed for a more conservative approach compared with the criteria to be considered for or offered preventive treatment, people with migraine who were eligible for preventive pharmacologic treatment were identified as those with ≥3 migraine headache days (MHDs) and severe disability (Migraine Disability Assessment Scale [MIDAS] grade IV [score ≥ 21]), ≥4 MHDs and some disability (MIDAS grade II [score 6–10] or grade III [score 11–20]), or ≥6 MHDs regardless of the level of disability, including little or no disability (MIDAS grade I [score 0–5])."

Using these consensus guidelines, across all countries in the survey, only 36.2% (5246 of 14,492) of respondents with migraine qualified for preventive medication. Of the respondents who qualified, 49.3% were currently taking acute prescription migraine medication. On average, the proportion of respondents who had ever used preventive medication was 19.3% (2799 of 14,492). Among these patients, slightly above half (58.1%) were still using preventive medication, and 41.9% had discontinued.

The highest rate of preventive medication ever use was in Japan (65.8%), while France was the lowest (51.1%). Among respondents not currently using a preventive medication, an average of 34.4% (4431 of 12,867) qualified for preventive treatment and among respondents with migraine currently using a preventive medication, an average of 50.2% (815 of 1625) still met the criteria for preventive treatment.

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"The large gaps in preventive medication use among those who qualify based on the 2021 AHS consensus statement may reflect a disconnection between providers and current treatment guidelines and between providers and people with migraine," the study authors noted. "Until recently, preventive migraine medications involved agents developed for diseases other than migraine (i.e., antihypertensives, antidepressants, antiseizure agents). While the evidence base is large for certain beta-blockers, candesartan, topiramate, and divalproex sodium, other widely used treatments are not well supported by rigorous clinical trials (e.g., amitriptyline, verapamil); additionally, many of these agents have significant adverse effects and some contraindications."

Additional data showed that the rates of both oral and injectable preventive medication used was 11.6% (189 of 1625) across countries and were lowest in France (1.3%) and highest in Germany (14.1%) and the United Kingdom (20.9%). Of note, onabotulinumtoxinA was the only available injection preventive medication in France and was available in all other countries except Japan. France and Japan had the highest rates of oral preventive medication use, with 97.1% and 88.3%, respectively.

Among the 4431 respondents who qualified but were not currently on preventive treatment, the majority (86.1%; n = 3815) had also never previously used preventive medication. In addition, when focusing on those currently using a preventive (n = 1625), 49.9% of patients did not still meet the criteria for preventive treatment based on the AHS consensus statement, suggesting that approximately half of the respondents with migraine were not receiving adequate benefit from their current medication.

In terms of limitations, Buse et al wrote, "Although the 2021 AHS consensus statement for preventive treatment eligibility provided conservative, uniform preventive treatment criteria across all countries, the reliability of the criteria has not been studied. Moreover, future studies incorporating the Canadian, European, or Japanese treatment guidelines to determine respondents’ eligibility for preventive treatment are warranted."

They added, "In addition to actual usage patterns among people who qualify for preventive treatment and to better address barriers to treatment, it would be helpful to further examine the proportion of people who were offered preventive medication, regardless of actual use, reasons that preventive medications were not offered, and reasons that people with migraine declined medication. Study strengths include the relatively large number of respondents across multiple countries and quality checks performed to eliminate unreliable survey respondents."

In April, the AHS published a statement claiming that calcitonin gene-related peptide (CGRP)-targeting therapies should be used as first-line treatments for migraine prevention. Prior to the newly published statement, the previous AHS consensus statements claimed that an individual try at least 2 classes of previous first-line migraine medications for at least 8 weeks before being considered for CGRP-targeting therapy. The focused AHS position statement was based on several reasoning factors, including the mounting evidence that establishes CGRP as a fundamental mechanism of migraine and CGRP-targeting therapies as “migraine-specific.”²

REFERENCE
1. Buse DC, Sakai F, Matharu M, et al. Characterizing gaps in the preventive pharmacologic treatment of migraine: multi-country results from the CaMEO-I study. Headache. 2024;64(5):469-481. doi:10.1111/head.14721
2. Charles AC, Digre KB, Goadsby PJ, Robbins MS, Hershey A. Calcitonin gene-related peptide-targeting therapies are a first-line option for the prevention of migraine: an American Headache Society position statetment update. Headache. Published March 11, 2024. doi:10.1111/head.14692