Prevalence and description of chronic daily headache in the general population in France.

The objective of this study was to describe the epidemiology, clinical presentation and consequences of chronic daily headache (CDH) in France. A representative nation-wide sample of the general population was identified using a stratified sampling method. Ten thousand five hundred and eight-five subjects were screened in face-to-face interviews, and data collected using a standard questionnaire. An overall point prevalence of CDH in the general population of 2.98% was observed. Two-thirds of these subjects presented migraine-like features. Severity, functional impact and healthcare consumption were higher than in subjects reporting episodic migraine in the same sample. Of the subjects, 28.2% reported the most severe migraine disability assessment scores (Grades 3 and 4), compared to 12% of episodic migraineurs. A qualité de vie et migraine score of 68.4 was observed, indicating severely attenuated quality of life. Only 6.6% of subjects were taking prophylactic treatment, whilst 88% were using non-specific acute headache treatments. The frequency of physician consultations and laboratory examinations was significantly higher than in individuals with episodic headache. CDH is thus a relatively prevalent condition in the general French population, associated with an important burden of suffering and with considerable expenditure in the health service. Management of this condition is generally inappropriate.