Last Updated: March 2001

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Epidemiology

Prevalence

In migraine, both the incidence and the duration of the illness determine prevalence. Historically speaking, the majority of migraine studies have emphasized prevalence. Although prevalence is extremely valuable for estimating the distribution of migraine, it may be more useful to look at the incidence of migraine when attempting to identify risk factors and examine disease associations.

Several reasons exist why collection and projection of epidemiologic data are difficult for migraine. One reason is the absence of objective diagnostic criteria. No definitive diagnostic test currently exists for migraine, and although some well-accepted diagnostic criteria do exist, they are not always used uniformly.

Other factors that make it difficult to collect accurate epidemiologic data include the need to rely on patient-reported symptoms and patients’ failure to consult physicians for migraine. Both factors are very significant. A 1989 national survey of U.S. migraineurs sponsored by the National Institutes of Neurologic Disorders and Stroke reported that only about one-half of patients seek medical attention for migraine, and only about one-half of those patients are properly diagnosed [Lipton et al., 1992]. About one-half of patients with a proper diagnosis of migraine receive prescription drugs [Celentano et al., 1992]. Because more than one study has demonstrated that about one-half of all migraineurs who meet the diagnostic criteria for migraine do not consult a physician, large, broad-based general population studies are critical if reliable epidemiologic data are to be collected.

It has been easier to collect broad-based epidemiologic data since the International Headache Society (IHS) developed specific diagnostic criteria. Despite differences in countries, populations, and years in which the studies were conducted, epidemiologic data regarding prevalence and other factors remain remarkably consistent. As shown in the table below, the prevalence of migraine for a 1-year period is about 10-12%: 6% among men and 15-18% among women. The latest epidemiologic data report that there are about 28 million migraineurs in the United States [Lipton et al., 2000].

Epidemiologic Observations of Migraine Prevalence in Industrialized Countries

Study (authors) Sample Source Number of Res-
pondents Age of Res-
pondents Time
Period
Prevalence % Male % Female % All

Breslau et al.
[1991]
United States Health maintenance organization 1007 21-30 Lifetime
1 year 7
3 16
13 13
NR*

D'Alessandro et al.
[1988]
Italy General population 1144 >7 1 year 9 18 16

Edmeads et al.
[1993]
Canada General population 2737 >15 Lifetime 9 23 16

Henry et al.
[1992]
United States General population 833 >15 Few years 6 18 12

Linet et al.
[1989]
United States General population 10,169 12-29 1 month 3 7 NR*

Lipton et al.
[2000]
United States General population 29,258 >12 Lifetime 7 18 13

Merikangas et al.
[1990]
Switzerland Results from screening scores 457 27-28 1 year 6 20 13

Rasmussen et al.
[1991]
Denmark General population 740 25-64 Lifetime
1 year 86 25
15 16
10

Stewart et al.
[1992]
United States General population 20,468 12-80 1 year 6 18 NR*

*NR = not reported.
Adapted from Rasmussen [1995]; with permission.

The overall prevalence of migraine is largely consistent in industrialized countries, despite variances of culture and other sociodynamic factors.

Similarly, an overview of data collected from various industrialized nations within the past 20 years reports a 1-year prevalence of migraine with aura of about 4% (see table below).

Comparison of Prevalence in Migraine with Aura

Country of Study Authors Migraine with Aura
All Patients (%) Prevalence
(Time Period)

Denmark Rasmussen et al. [1992] 4 1 year

Switzerland Merikangas et al. [1990] 4.6 About 1 year

United States Breslau et al. [1991] 5.9 1 year

Israel Abramson et al. [1980] 2.1 About 1 year

Nigeria Ogunyemi [1984] 3.4-5.1 About 1 year

In general, the 1-year prevalence of migraine is about 4%.
From Rasmussen [1994]; with permission.

Migraine without aura is more common than migraine with aura. In a Danish study of a representative general population, the lifetime prevalence of migraine with aura was 6%, whereas the prevalence of migraine without aura was 9%. Importantly, 1.2% of the population reported having both types of migraine [Rasmussen, 1995].

According to another analysis, the lifetime prevalence of tension-type headache is about 69%, whereas migraine occurs in about 15% of the population worldwide. The prevalence of cluster headache (0.1%) and other primary headache forms is relatively low [Rasmussen, 1995]. These figures also are based on the diagnostic criteria that the IHS classification system established.

However, these figures underestimate the importance of migraine in headache patients seen by physicians. At least two Market Measures, Inc., studies report physicians having the perception that nearly one-third of their headache patients are being treated for migraine [1997]. Similarly, although the prevalence of cluster headache is reported as 0.1%, physicians say they treat 4% of their headache patients for cluster headache. The stronger pain intensity and disability associated with migraine and cluster headaches (as opposed to tension-type headaches), which may increase the likelihood that patients with migraine and cluster headaches will seek treatment, may explain this disparity between prevalence and physician treatment percentages.

Gender and Age Prevalence

According to four recent studies conducted in France, Denmark, and the United States, which used IHS criteria to define migraine, the prevalence of migraine is about 6% among men and 15-17% among women (see figure below).

Gender-Specific Prevalence of Migraine as Defined by IHS Criteria in Four Population-Based Studies

Adapted from Stewart et al. [1994]; with permission.
Click on image for larger version.

Beginning at age 12, the prevalence of migraine increases in both males and females and continues to increase until age 40, after which it decreases. Before the onset of puberty, prevalence in males may be similar to that in females; however, prevalence increases more rapidly in females after age 12 (see figure below).

Age- and Gender-Specific Prevalence of Migraine

From Lipton and Stewart [1993]; with permission.
Click on image for larger version.

As a result, the female-to-male ratio increases from menarche to about age 40. After age 40, the female-to-male ratio decreases (see following figure), suggesting a role for cyclical hormone levels in the pathophysiology of migraine.

Female-to-Male Prevalence Ratio of Migraine by Age

From Lipton and Stewart [1993]; with permission.
Click on image for larger version.

Although decreasing estrogen levels may account for some variation in the female-to-male ratio with age, other factors are likely to be involved, because prevalence remains higher in women than in men well beyond the average age of menopause.

By contrast, the typical cluster headache patient is a middle-aged man, with men being affected five times more often than women.

Socioeconomic Status

Contrary to popular belief, migraine is not more common among patients with higher income levels, although migraine awareness and medical diagnoses do rise with income (see table below).

Income-Specific Prevalence of Migraine

Migraine Prevalence

Household Income (United States) Female Male

<10,000 20.8 7.4

10,000 - 19,999 17.8 6.6

20,000 - 29,999 17.9 5.9

30,000 - 44,999 16.3 5.9

>/=45,000 16.3 5.3

From Stewart et al. [1992]; with permission.

Results of several recent, population-based studies have revealed that migraine prevalence is inversely related to socioeconomic status. The prevalence of migraine is generally higher in the groups with low income and education.

Although it is not certain why the prevalence of migraine is higher in low-income groups, several possible explanations have been explored. Higher prevalence of migraine in low-income groups may be due to higher incidence or longer duration of the disorder. In the United States, individuals in higher income groups tend to have wider access to medical care and also tend to seek medical consultation more readily than individuals in lower income groups. Both these factors may result in decreased duration, and therefore lower prevalence, of migraine. Higher prevalence of migraine among individuals in low-income groups may also result from factors associated with both migraine and low income, such as stress or diet. Migraine may also interfere with education or job performance and place the individual in a lower income bracket because of loss of income or inability to gain the skills necessary to achieve a higher income.

References

Abramson JH, Hopp C, Epstein LM. Migraine and non-migrainous headaches: a community survey in Jerusalem. J Epidemiol Community Health. 1980;34:188-193.

Breslau N, Davis GC, Andreski P. Migraine, psychiatric disorders, and suicide attempts: an epidemiologic study of young adults. Psychiatry Res. 1991;37:11-23.

Celentano DD, Stewart WF, Lipton RB, et al. Medication use and disability among migraineurs -- a national probability sample survey. Headache. 1992;32:223-228.

D’Alessandro R. Benassi G, Lenzi PL. Epidemiology of headache in the Republic of San Marino. J Neurol Neurosurg Psychiatry. 1988;51:21-27.

Edmeads J, Findlay H, Tugwell P. Impact of migraine and tension-type headache on life style, consulting behaviour, and medication use: a Canadian population survey. Can J Neurol Sci. 1993;20:131-137.

Henry P, Michel P, Brochet B. A nationwide survey of migraine in France: prevalence and clinical features in adults. Cephalalgia. 1992;12:229-237.

Linet MS, Stewart WF, Celentano DD. An epidemiologic study of headache among adolescents and young adults. JAMA. 1989;261:2211-2216.

Lipton RB, Diamond S, Reed M, et al. American Migraine Study II: prevalence, burden, and health care utilization for migraine in the United States. Headache. 2000;40:416.

Lipton RB, Stewart WF. Migraine in the United States: a review of epidemiology and health care use. Neurology. 1993;43(suppl 3):S6-S10.

Lipton RB, Stewart WF, Celentano DD, et al. Undiagnosed migraine headaches -- a comparison of symptom-based and reported physician diagnosis. Arch Intern Med. 1992;152:1273-1278.

Market Measures, Inc. Medical Marketing Conference: Treatment of Migraine Study II Analytical Report, April 1997.

Merikangas KR, Angst J, Isler H. Migraine and psychopathology. Arch Gen Psychiatry. 1990;47:849-853.

Ogunyemi AO. Prevalence of headache among Nigerian university students. Headache. 1984;24:127-130.

Rasmussen BK. Epidemiology of migraine. Biomed Pharmacother. 1995;49:452-455.

Rasmussen BK, Olesen J. Epidemiology of migraine and tension-type headache. Curr Opin Neurol. 1994;7:264-271.

Rasmussen BK, Jensen R, Schroll M. Interrelations between migraine and tension-type headache in the general population. Arch Neurol. 1992;49:914-918.

Rasmussen BK, Jensen R, Schroll M. Epidemiology of headache in a general population -- a prevalence study. J Clin Epidemiol. 1991;44:1147-1157.

Stewart WF, Lipton R, Celentano DD. Prevalence of migraine headache in the United States. JAMA. 1992;267:64-69.

Stewart WF, Shechter A, Rasmussen BK. Migraine prevalence: a review of population-based studies. Neurology. 1994;44(suppl 4):S17-S23.

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