Headache may have considerable economic consequences, both for the patient and for the society as a whole. There are more studies about the societal costs than about the individual economic losses of the patients.
Relation to socioeconomic status, education and employment
In a large Norwegian study (the HUNT study), both migraine and headache in general was associated with low socioeconomic status [
4], which has also been found in North America [
5,
6] but not in some smaller European studies [
7‐
11]. The question whether this is a consequence or a cause of headache is not satisfactorily answered, but in one Swedish study, half of the patients reported a negative influence of migraine on their ability to pursue studies and one third a negative influence on their finances [
9]. In a US study it was found that headache patients have somewhat reduced labour force participation [
12], but employment status has not been found to be related to headache in some European studies [
7,
13].
Absenteeism from work
In two relatively old studies, one from Finland in 1979 [
14] and one from San Marino in 1986 [
15], 7% of working individuals had been absent from work in the previous year due headache. In a Danish study of 1992 [
16], it was found that 43% of migraineurs (5% of the population) and 12% of TTH patients (9% of the population) had been absent from work during the previous year due to headache, i.e. a total of 14% of the population. In a Swedish study of 2004 [
9], it was found that 65% of migraineurs reported some degree of absence from either school or work during the previous year. These data are, however, of relatively limited interest from an economical viewpoint as they do not indicate the number of days that the headache sufferers are away from work.
The number of days with work absence due to headache is relatively consistent across studies from different countries. In some previous studies it has varied between 2 and 6 days per year among headache patients in general [
17], and between 1.5 and 4.2 days per year in migraineurs [
9]. A study among migraineurs in Sweden revealed that 35% were never absent from work due to migraine, and 54% were absent 1–2 days per year [
9]. Compared to headache-free individuals, migraine patients in the HUNT study from Norway lost on average 4.4 workdays per year, and persons with non-migrainous headache lost 2.5 workdays per year [
18]. In the Danish study from Copenhagen [
16], the TTH patients who had been absent seem to have been as much or more absent from work than the migraine patients, and the number of workdays lost due to migraine was 270 and to TTH 820 per 1,000 persons per year, i.e. a total of 1,090 days. In a study from England in 2003 [
13], 15% had been absent from work or had reduced ability to work due to headaches in the previous 3 months. Per year, headache accounted for 1,327 missed and 5,213 reduced ability days per 1,000 workers per year, representing 0.5 and 2.0% of all working days in the adult population, irrespective of headache status. This study did not relate absenteeism to different headache diagnoses. In an English study of 2003, an estimated 5.7 workdays per year was missed by migraineurs working or attending school [
8]. This seems to be higher than in France where a diary-based registration of absenteeism published in 1999 showed that migraineurs were away from work 2.18 days per year due to headache [
19].
Health economic studies
For the headache part of the “Cost of Brain Disorders in Europe” project, a literature search for studies containing cost data for migraine and other headaches identified eight European studies evaluating the direct or indirect costs of migraine from a societal perspective [
20], from France [
22,
23], Germany [
24], The Netherlands [
25], Spain [
26], Sweden [
27] and the UK [
28,
29]. No studies analysing the cost of TTH or other non-migraineous headaches were found. There were large variations in costs across the six European countries where data were available, ranging from around €100 per patient per year in Sweden to nearly €900 in Germany. These variations are probably mostly due to different methodologies and differences in the year when the studies were conducted. An important finding was that the vast majority of total costs, between 72 and 98%, was indirect costs, due to lost productivity, either in the form of work absence or reduced efficiency levels when working with migraine. Women tended to lose more workdays than men, but indirect costs were similar due to lower salaries and labour force participation amongst women. The direct costs, related to consultation, diagnostic investigations, treatments, and hospital admissions accounted for less than 30% of total costs in most studies.
The cost estimate for migraine in the European report was based on an average of the most representative cost estimates, from the UK, Germany and France. An average annual cost of €585 per migraine patient was estimated for these Western European countries. The 1-year prevalence of migraine was 14% among adults in Europe according to the review of epidemiological studies [
1], i.e. 41 million adult Europeans with active migraine. Per patient migraine was the least costly disorder among the brain disorders. However, due to the high prevalence, the total cost of migraine was estimated to be €27 billion for whole Europe in 2004, which was the highest cost among the purely neurological disorders. Many of the psychiatric afflictions were even more costly according to this review. It is, however, likely that the available cost data in Europe would tend to underestimate the actual costs of headache, mainly because no cost data existed on the most common headache type (TTH), but also because children and adolescents were not considered, and because cost connected with more expensive medication (triptans) were not included, since most cost studies were performed before this class of drugs was introduced.
In a separate paper summarizing the prevalence and cost data for headache in Europe [
30] a more speculative estimate for the cost of headache, rather than migraine alone, was derived by using the results of the Danish [
31] and British [
32] population-based studies which demonstrated that around 1,100–1,300 days per 1,000 workers were missed due to headache each year. The British study also suggested that the number of days with reduced efficacy was around four times higher than the number of days missed. Assuming a reduced efficiency of 35% when working with headache, and that the direct costs of headache constitute the same proportion of the total costs as for migraine, the average total cost per headache patient was estimated to be roughly €420 per year (of which €390 would be due to indirect costs and €30 due to direct medical costs). Since headache in general was found to affect nearly 50 % of Europeans, this estimate, if true, would make headache a much more costly disorder than migraine alone.
It is of interest to compare the European cost study [
3] with more recent cost studies in some individual European countries. In one study from Spain [
33] the annual costs of migraine was only about 50% of the sum given in the European Cost study for the same country. The difference may partly be explained by somewhat lower prevalence figures (12 vs. 14%) for migraine used in the Spanish study, but the main difference may be that this study did not employ a bottom-up design, but used published statistics and data to estimate resource use and productivity losses, which may have led to an underestimation of some costs. A recent study from France [
34], restricted to the direct costs in 1999, found that these costs were at least twice as high (€128) as in the European migraine cost study (<€60). This study included both “strict” migraine (IHS 1.1 and 1.2) and “migraineous disorder” (IHS 1.7, corresponding to 1.6 in ICHD-2), which together affected 17% of the population. For the whole country the direct costs amounted to more than 1 billion €, which was 0.068% of the gross national product. Non-migraineous episodic headache, affecting 9.2% of the population, entailed a considerably lower cost of €28.
It may also be of interest to compare the European studies with one US study using a quite different methodology to assess direct costs. In this study, all types of medical care costs (not only those related to headache) were derived from the claims records of a large health plan, whereas diagnostic status (migraine or not) and comorbid and demographic status was ascertained using a telephone interview among members of the health plan [
35]. Migraineurs incurred on average $700 more per year in total medical care costs than the controls. Interestingly, this statistically significant difference disappeared when psychiatric comorbidity variables (anxiety and depression) were entered into the model. The much higher costs per patient reflected in this study than in the French study [
34] and Spanish study [
33] may therefore at least partly be due to the differences in cost assessment methodology, indicating that the direct costs specifically related to migraine and not to comorbid disorders are most reliably assessed by a direct method, questioning patients about use of health-care resources.
Medication for headache constitutes an important part of the direct costs. In France in year 2000, the most frequently used acute medications for migraine were paracetamol, salicylates and NSAIDs. Triptans were used by 8% of migraineurs, and prophylactic treatment was used by 6% [
36]. In Denmark 26% of migraineurs had used triptans in 2001, but less than 5% of those with pure migraine had used prophylactic medication [
37].