Multiple sclerosis (MS) is a chronic and potentially highly disabling disorder with considerable social impact and economic consequences. It is the major cause of non‐traumatic disability in young adults. The social costs associated with MS are high because of its long duration, the early loss of productivity, the need for assistance in activities of daily living and the use of immunomodulatory treatments and multidisciplinary health care. Available MS epidemiological estimates are aimed at providing a measure of the disease burden in Europe. The total estimated prevalence rate of MS for the past three decades is 83 per 100 000 with higher rates in northern countries and a female:male ratio around 2.0. Prevalence rates are higher for women for all countries considered. The highest prevalence rates have been estimated for the age group 35–64 years for both sexes and for all countries. The estimated European mean annual MS incidence rate is 4.3 cases per 100 000. The mean distribution by disease course and by disability is also reported. Despite the wealth of epidemiological data on MS, comparing epidemiological indices among European countries is a hard task and often leads only to approximate estimates. This represents a major methodological concern when evaluating the MS burden in Europe and when implementing specific cost‐of‐illness studies.

Aims: We tested the usability and usefulness of the basic diagnostic headache diary (BDHD) for the diagnosis of migraine, tension-type headache and medication-overuse headache in European and Latin American countries. Methods: Patients were subdivided into two groups according to a 1:1 randomization list. Those in group 1 were sent the BDHD before their first visit to the headache centre and asked to complete it for at least 1 month. Those in group 2 made their first visit to the headache centre without receiving the BDHD. Results: A total of 626 patients from nine countries and 16 centres completed the study. The BDHD entries were complete in 97.5% of cases. BDHD information and clinical interview were, when taken together, considered complete for diagnosis in 97.7% of cases in group 1 whereas the information obtained by clinical interview alone in group 2 was considered complete in only 86.8% of cases (p < 0.001). The median number of diagnoses per patient in group 1 was significantly higher than in group 2 (p = 0.04). The BDHD was very well accepted by both patients and doctors. Conclusions: It is concluded that the BDHD is a useful tool in the diagnostic assessment of the most frequent and disabling forms of primary headache and in headache management.