Indirect costs attributed to headache: A nation-wide survey of an active working population.

Background: The economic burden of headache in European countries is substantial, mostly related to indirect work-productivity loss costs, yet data for Portugal is scarce.
Methods: An anonymous web-based survey of headache was distributed to a convenience sample of Portuguese companies' workforces, to assess last-year headache and "yesterday"-point prevalence. Preexisting headaches were classified into migraine and non-migraine headache and work impact (absenteeism and presenteeism) was evaluated in relation to point prevalence. If no significant selection biases were detected, projected work-loss costs for the whole country were to be calculated.
Results: Eleven (17%) of 65 invited companies participated, around 15,000 active workers were exposed to the survey and 3624 (24.3%) responded, 73% females, 84.3% with previous ("last-year") headaches, 53% with migraine. Due to participation and gender bias, national cost-projections were not calculated. Workday point-prevalence was 21% (migraine) and 9% (non-migraine headache), resulting in 14 employees with migraine losing, on average, 4 h and 32 min of work time. Presenteeism occurred in 29% of migraine and 15% of NMH employees. Yearly cost of each employee with a headache disorder was €664.88.
Discussion: Headache has a significant economic burden, as measured by work loss costs, in Portugal. Company-based interventions should aim to support employees' access to headache diagnosis and treatment, including non-pharmacological coping strategies, in order to reduce headache related economic costs.