Reduction in medication-overuse headache after short information. The Akershus study of chronic headache

Objective: Our aim was to investigate the course of medication-overuse headache in the general population and the effect of simple advice regarding medication overuse. Design: Prospective cohort study. Participants were identified in a cross-sectional epidemiological sample of 30 000 persons aged 30-44 from the general Norwegian population. People with chronic headache (>= 15 days per month for at least 3 months) and medication overuse received short information about the possible role of medication overuse in headache chronification. A cohort was followed up 11/2 years later. The diagnostic criteria of the International Classification of Headache Disorders and data splitting methodology were used. Setting: Akershus University Hospital, Oslo, Norway. Participants: A total of 109 participants with chronic primary headache and medication overuse were available for follow-up (85% participation rate). Main outcome measure: Change in medication days and headache days per month. Results: At baseline chronic tension-type headache was found in 92% of participants; 8% had chronic migraine or new daily persistent headache. Migraine co-occurrence was found in 53%. The mean duration of chronic headaches were 8-18 years, the mean duration of medication overuse between 5 and 10 years prior to intervention. At follow up, the mean medication days were significantly reduced from 22 days to 6 days per month, and 76% no longer had medication overuse. Forty-two percent no longer had chronic headache and the headache index was reduced by 24%. Conclusion: Our examination and short information served as a modified brief intervention which can improve chronic headache and medication overuse in the general population.