Prevalence of headache disorders in Norway: results from the population based PopHEAD study

Reliable and up-to-date prevalence estimates of headache disorders are essential for public health planning. Despite previous large-scale studies, there is a lack of validated and up-to-date population-representative prevalence estimates from Europe. Here, we aimed to estimate the one-year prevalence of the major headache disorders in Norway using a validated diagnostic tool. PopHEAD is a population-based Norwegian cross-sectional study. A random sample of 28,753 individuals aged 18–70 years was invited to complete a digital version of the Headache-Attributed Restriction, Disability, Social Handicap and Impaired Participation (HARDSHIP) questionnaire, adapted and translated into Norwegian. Headache diagnoses were made using a standardized algorithm based on the International Classification of Headache Disorders (ICHD-3) criteria and validated by telephone interview in a sub-sample. Prevalence estimates were calculated as crude proportions with 95% confidence intervals and sequentially adjusted for age and sex, measurement error and selection bias. Associations with demographic variables were investigated. A total of 8,265 participants (3,344 men and 4,921 women; mean age 47.3 years) responded. The crude one-year prevalence was 29.6% for migraine (36.5% in women, 19.4% in men), 52.7% for tension-type headache (TTH) (51.4% in women, 54.6% in men), and 5.1% for probable medication-overuse headache (pMOH) (6.5% in women, 3.1% in men). After adjusting for age, sex, measurement error, and selection bias, the estimated prevalence was 20.3% for migraine, 47.9% for TTH, and 5.9% for pMOH. Migraine prevalence was highest among participants with low income and low education, while TTH prevalence was highest in participants with high socioeconomic status. pMOH prevalence was highest in participants aged 26–45 years and in participants with low education. The PopHEAD study provides updated, validated and bias-adjusted prevalence estimates for migraine, TTH and pMOH in the Norwegian adult population. These data may inform health resource allocation for headache management in similar populations.