The incidence and prevalence of cluster headache: a meta-analysis of population-based studies.

Cluster headache is a trigemino-autonomic cephalgia with a low prevalence. Several population-based studies on its prevalence and incidence have been performed, but with different methodology resulting in different figures. We analysed all available population-based epidemiological studies on cluster headache and compared the data in a meta-analysis. The pooled data showed a lifetime prevalence of 124 per 100,000 [confidence interval (CI) 101, 151] and a 1-year prevalence of 53 per 100,000 (CI 26, 95). The overall sex ratio was 4.3 (male to female), it was higher in chronic cluster headache (15.0) compared with episodic cluster headache (3.8). The ratio of episodic vs. chronic cluster headache was 6.0. Our analysis revealed a relatively stable lifetime prevalence, which suggests that about one in 1000 people suffers from cluster headache, the prevalence being independent of the region of the population study. The sex ratio (male to female) is higher than published in several patient-based epidemiological studies.