A new study reveals the growing burden of headache disorders, with evidence suggesting that 52% of the global population is affected.
Headache disorders are one of the most prevalent and disabling conditions worldwide. The most common types of headaches include tension, cluster, migraine, allergy and caffeine headache. There is great variation in studies surrounding the topic of headache disorders with contrasting methods and samples utilised, which could impact how global rates are estimated.
Bringing together headache disorder studies, researchers from the Norwegian University of Science and Technology reviewed 357 publications between 1961 and the end of 2020 to estimate the global prevalence of headaches.
The review is published in The Journal of Headache and Pain.
The global prevalence of headache disorders
The research team analysed over 350 studies, with the majority focussing on adults between 20 and 65, however, a selection of research was carried out on adolescents, children aged five and over and elderly people aged 65.
Building on a previous report from 2007, Lars Jacob Stovner and colleagues also measured the differences in methods across the studies they reviewed. They modelled these differences in methods and how they are associated with estimates of headache disorder prevalence. Most studies reported on headache prevalence during the past year. Whilst some studies reported headache disorder prevalence across the whole life and some for much shorter periods, including instances of headache within the last day.
The authors estimate that 52% of the global population have experienced a headache disorder within a given year, with 14% reporting a migraine, 26% reporting a tension-type headache and 4.6% reporting a headache for 15 or more days per month. From the 12 studies that reported headaches during the last day, the authors estimate that 15.8% of the world’s population have a headache on any given day, and almost half of those individuals report a migraine (7%).
Lars Jacob Stovner, the lead author, said: “We found that the prevalence of headache disorders remains high worldwide and the burden of different types may impact many. We should endeavour to reduce this burden through prevention and better treatment. To measure the effectiveness of such efforts, we must be able to monitor the prevalence and burden in societies. Our study helps us understand how to improve our methods.”
All types of headache disorders were more common in females than males, most markedly for migraines (17% in females compared to 8.6% in males) and headaches for 15 or more days per month (6% in females compared to 2.9% in males).
Study methods and headache estimates
The research team looked at the association between study methods and headache estimates. Some of the various measures included screening questions, sample size, publication year, and how diagnostic criteria are applied, amongst others, explained 29.9% of the variation in migraine estimates and less for other headache disorders. This suggests that there may be other methodological factors accounting for the greater variations across the studies. When modelling the variation in migraine prevalence estimates, the publication year of studies was associated with 6% of the variation in headache estimates, with higher prevalence estimates associated with a more recent publication. The authors propose that this might reflect migraines becoming more common over the last three to four decades or suggest improved methods of diagnosing migraines.
Furthermore, the authors acknowledge that the majority of publications they reviewed came from high-income countries with good healthcare systems, so this may not reflect every country. This presents a future investigation into low and middle-income countries to present a more accurate global estimate of headache disorder prevalence.