Monitoring chronic headache and medication-overuse headache prevalence in Denmark.

Objectives: To study chronic headache and medication-overuse headache (MOH) prevalence; to identify groups with high prevalence of these conditions; and to identify the most frequently used pain medications among respondents with chronic headache.

Background: Chronic headache and MOH prevalence in Denmark were last estimated in 2010.

Methods: In this cross-sectional study, 104,950 individuals aged ≥16 years were randomly sampled for the 2017 Danish Capital Region Health Survey.