Cluster headache and comorbidities, income and education: A nationwide registry-based matched cohort study.

BackgroundTo investigate whether epidemiological characteristics, including comorbidities, income, and education, have changed over time in people with cluster headache compared to controls.MethodsTrends in cardiopulmonary, neurological, and psychiatric comorbidities, and income and education categories, were assessed using linked data from Norwegian health registries for 2009-2022. Comorbidities were defined based on relevant diagnosis codes from both the primary and the specialist healthcare. Income was categorized based on the national median for each year. Education was assessed based on the International Classification Standard for Education. Each cluster headache case was matched with 20 controls without cluster headache. Prevalence rate ratios were calculated using generalized estimating equations.ResultsPeople with cluster headache had higher prevalence than matched controls without cluster headache in all examined comorbidities, particularly migraine (men: 9.8% versus 0.3%; women: 23.1% versus 1.6%), mood disorders (men: 6.7% versus 2.8%; women: 9.2% versus 4.9%), and pulmonary disorders (men: 3.0% versus 1.8%; women: 4.8% versus 2.3%). Hypertension, coronary heart disease, and psychiatric disorders in specific age- and sex groups increased more in people with cluster headache than in controls during the recording period. Low/medium income was more prevalent in people with cluster headache versus controls (men: 50.2% versus 42.2%; women: 51.4% versus 46.6%). Similarly, low/medium education was more prevalent in people with cluster headache than controls (men: 77.0% versus 65.1%; women: 65.0% versus 55.0%). The prevalence of low/medium education increased in young women during the recording period.ConclusionsPeople with cluster headache have a higher prevalence of comorbidities compared to matched controls, particularly migraine, mood disorders, and cardiopulmonary disease. Multiple comorbidities have increased in prevalence over time. Annual income and years of education were lower in people with cluster headache compared to matched controls. Cluster headache is a complex disease that requires specialist follow-up and individualized therapy.