Epidemiology of medication overuse headache in the general Swedish population

Aims: The aim was to estimate the prevalence of medication overuse headache (MOH) in Sweden and to analyze the occurrence of this disorder in different population groups. Methods: A total of 44,300 randomly selected individuals (55% women), aged 15 years and above, were interviewed in a national telephone survey, using a standardized questionnaire including the International Headache Society criteria for MOH and questions about sociodemographic factors, headache history and medication use. Results: In Sweden, 3.2% (95% confidence interval (CI) 3.1-3.4), n = 1428) suffer from chronic daily headache (CDH) and out of those, 56% (n = 799) have MOH. The prevalence of MOH is 1.8% (95% CI 1.7-1.9). The mean age of onset was higher among men than women as well as among those with tension-type headache as primary headache compared to those who originally had migraine. A multivariate analysis showed that socioeconomic factors such as having a low level of education and/or a low household income were associated with MOH. Conclusions: This is the first Swedish population-based study of MOH and we conclude that MOH is a significant public health problem in Sweden, as it is in other parts of the world.