Barriers to Medication Adherence in People Living With Epilepsy

Epilepsy affects approximately 1.2% of the US population, resulting in 3.4 million Americans with active epilepsy. Antiseizure medication (ASM) is considered the mainstay of treatment, effective for two-thirds of people with epilepsy (PWE), while at least one-third experience drug-resistant epilepsy. A significant percentage of PWE who are treated with ASMs report nonadherence to this type of medication, leading to potentially preventable seizures and the potential for being inappropriately classified as having drug-resistant epilepsy. Ongoing seizures are associated with increased morbidity, mortality, and health care costs, among other consequences. Recognizing when PWE struggle with ASM adherence is essential for creating effective interventions and prevention strategies to improve patient outcomes.

As part of the Epilepsy Learning Healthcare System Registry, we collected data from 2020 through 2023 from 4,917 individuals seen at 8 epilepsy clinics in the United States. In this cross-sectional study, we used logistic regression analysis to examine the relationship between patient-reported seizure control (or provider-reported seizure control for some sites) and endorsed barriers to medication adherence. In addition, we explored potential associations with demographic variables such as sex, race, and ethnicity. The data analysis was conducted using R version 2023.06.1 + 524.

Overall, 18.4% (893/4,848) reported adherence barriers and 37.7% (1,447/3,834) reported seizure control, defined as no seizures for the preceding 12 months or longer. The most prevalent barriers were forgetting to take ASMs (48.2%), experiencing ASM side effects (29.2%), and feeling as if the ASMs were not helping in controlling seizures (21.3%). The PWE who reported adherence barriers had 0.6 lower odds of having seizure control compared with those who did not report barriers (95% CI 0.4-0.7) and 0.6 lower odds of having seizure control after adjusting for race, ethnicity, and sex (95% CI 0.5-0.7).

We observed significant barriers to medication adherence and inadequate seizure control among adult PWE across 8 centers in the United States. This study suggests that PWE might benefit from standardized screening for adherence barriers with behavioral strategies to address these barriers offered during clinical encounters to personalize care.