Objective: To evaluate the evidence for quality of life (QoL) impairment, disability, healthcare resource use and economic burden associated with chronic daily headache (CDH), focusing on chronic migraine (CM) with or without medication overuse.
Methods: A systematic review and qualitative synthesis of studies of patients/subjects with CDH that included CM, occurring on at least 15 days per month.
Main findings: Thirty-four studies were included for review (25 studies of patients and nine of subjects from the general population). CDH and CDH with medication overuse headache (MOH) were consistently associated with a lower QoL compared to control or episodic headache (EH) and CDH without MOH. CDH was consistently associated with greater disability and productivity loss, more consultations, more or longer hospitalizations and higher direct costs than EH. Data were not amenable to statistical pooling.
Principal conclusions: The findings of this review underline the detriment to QoL and the disabling nature of CDH, and in particular CM and CDH with MOH, and negative impact on workplace productivity compared to other types of headache.