Prevalence of epilepsy in Portugal: An epidemiologic population-based study (EPIPORT)

Epilepsy is prevalent among ∼50 million people worldwide. Updated information is lacking on the epidemiology and characteristics of epilepsy in Portugal. Therefore, a population-based study was conducted to estimate the prevalence and identify potential undiagnosed cases of epilepsy in children and adults in Portugal.

This cross-sectional population-based study, conducted from May 2023 to July 2024, involved a nationwide door-to-door survey in Portugal (mainland and islands), screening 10,666 individuals. Trained interviewers visited selected households to recruit and interview participants, applying questionnaires to identify undiagnosed epilepsy cases and gather information about positive epilepsy diagnosis and management. Participants reporting positive screening were further evaluated by steering committee epileptologists for a potential epilepsy diagnosis.

The study estimated a crude prevalence of epilepsy of 9.76 cases per 1000 people (95% CI 86,7-115,5) in Portugal. The average age of the prevalent cases was 44.22 years (±21.99). Epilepsy was more common among females (55.8%), adults (∼82%), and residents of the North (45.5%), Center (26.6%), and Lisbon (15.3%) regions. Around 20% of the participants had not experienced seizures in the last 10 years. Also, ∼44% of the participants were taking three or more antiseizure medications.

The study indicates that Portugal's epilepsy prevalence is twice as high as reported in a 1998 study conducted in the north of Portugal and exceeds both global and European averages. Due to limitations such as the small number of confirmed cases and low physician contact rates, the representativeness of the study in certain regions or age groups should be interpreted with caution. Nevertheless, the high burden of epilepsy highlights the need for effective health programs and resource allocation.