American Migraine Study II

Fact Sheet
A study conducted for the National Headache Foundation (NHF) and underwritten by a grant from Glaxo Wellcome Inc. (now GlaxoSmithKline) measures the prevalence of migraine headache in America and quantifies the impact this disabling disease has on the lives of migraine sufferers.

Despite the development of medications specifically designed to treat migraine over the past decade, the study shows most patients are not receiving optimal treatment. In a startling comparison between the new data and that of a similar study conducted in 1989, it was found that patient treatment has not kept pace with scientific breakthroughs. Migraine is a legitimate, biological disease characterized by throbbing head pain, usually located on one side of the head, often accompanied by nausea and sensitivity to light and/ or sound. Migraine is more common than asthma, diabetes or congestive heart failure. The combination of disabling pain and associated symptoms often prevents sufferers from performing daily activities. Attacks occur periodically and can last from four to 72 hours. Symptoms, incidence and severity vary by individual and by attack.

Study Background

• The American Migraine Study was conducted in 1989 to assess the burden of migraine in the U.S. population.
• Findings of this initial study were published in Journal of American Medical Association[1] in 1992.
• American Migraine Study II used the same methodology as the original study but assessed the migraine prevalence, diagnosis, disability and medication usage patterns in the U.S.
• Topline results of American Migraine Study II were released at the 13th Annual Conference of the Diamond Headache Clinic Research and Education Foundation in 2000.
• Final comprehensive findings of American Migraine Study II — A Ten Year Report Card, are published in Headache[2] in 2001. Study authors include Lipton R, Diamond S, Reed M, Diamond M and Stewart W.

Study Objectives

• Measure the prevalence of migraine headaches in the American population
• Assess the impact of migraine headaches on the daily lives of patients
• Measure changes in migraine management between 1989 and 1999

Study Methods

• The mail survey was conducted by Strategic Insights, Inc., using the National Family Opinion (NFO) household panel constructed to match national demography.
• A 20-item symptom screening and impact questionnaire was mailed to 20,000 U.S. households in Spring 1999.
• 13,869 completed questionnaires were returned (a 69.3 percent response rate) and included data for 29,258 individuals aged 12 and older. A total of 6,211 severe headache sufferers were identified.
• This study replicates methods used in the 1989 American Migraine Study, results published by Stewart, Lipton et. al in JAMA, 1992, Vol. 267, No. 1, pages 64-69.
• The migraine symptom criteria of the International Headache Society (IHS) were used to identify potential migraineurs.

Summary of Findings
Approximately 28 million people in the United States aged 12 and older ­ approximately 13 percent of the population ­ suffer from headaches that fit the medical definition of migraine established by the IHS. This is equal to one migraine sufferer in every four U.S. households. The percentage of patients whose headaches fit the medical definition of migraine who are being diagnosed has increased compared to a decade ago. However, more than half of these sufferers still have never received a physician diagnosis of migraine (52 percent) and most are not receiving the most appropriate treatment, despite new and effective therapies designed specifically to treat the pain and symptoms of migraine . There have been no dramatic changes in the way physicians approach the treatment of migraine in the past 10 years.

Key Findings

• Total U.S. migraine prevalence was virtually the same in 1999 (12.6 percent of the total population aged 12 and older) vs. 1989 (12.1 percent). However, the total number of sufferers has increased from 24 million in 1989 to 28 million in 1999.
• Females are more likely to be diagnosed by a physician with migraine. This may be due to the higher prevalence rate among women and a corresponding sensitivity among physicians to screen for migraine. The greater propensity of women to consult their physician for health problems and routine examinations may also contribute to this finding.
• Since there have been significant advances in treatment, including the development of migraine specific therapies over the past 10 years, one might think the medical approach to migraine would have changed dramatically in that time. It has not. Nearly six out of 10 (57%) sufferers continue to use over-the-counter (OTC) remedies exclusively to manage their headaches. It also suggests physicians have not significantly changed their approach to migraine treatment despite the introduction of migraine specific therapies.
• The continued high use of OTCs is even more surprising given the significant increase in the number of sufferers reporting a physician diagnosis of migraine (38 percent in 1989 vs. 48 percent in 1999).
• Diagnosed patients report a similar pattern of suffering which highlights that appropriate treatment is a vital component of care. Patients report these symptoms:
• Many patients continue to suffer needlessly:
  • An average of 80 percent of diagnosed and undiagnosed sufferers say their headaches are severe or extremely severe. In fact, the percentage of sufferers who report severe pain is nearly the same in diagnosed and undiagnosed patients.
  • 43 percent of migraine sufferers report headache pain five or more days in the last three months
  • Migraine is misdiagnosed as tension (a catch-all phase) or sinus headache (a relatively rare condition) almost as frequently as it is correctly diagnosed
  • A majority of all migraine sufferers (53 percent) characterize their pain as causing either severe impairment or forcing them to retreat to their beds ­ sometimes for days at a time
  • 38 percent suffer three years or more before being diagnosed with migraine by a physician[3]
  • More than half (51 percent) of sufferers report a 50 percent or more reduction in work and/or school productivity; 67 percent report a 50 percent or more reduction in household work productivity
  • Nearly one quarter of migraine sufferers (24 percent) report headaches so severe that they sought care in either an emergency room or urgent care clinic[4]