Associations Between Social Determinants of Health and Epilepsy Prevalence in U.S. Adults: NHANES1999–2018

Background Epilepsy is a common neurological disorder influenced by multiple social determinants of health (SDoH). However, the joint effects of SDoH and their relative contributions remain unclear. Methods We analyzed data from 36,458 participants in the National Health and Nutrition Examination Survey (NHANES) 1999–2018. Epilepsy was defined using specific anticonvulsant medications to improve specificity. Eight SDoH factors were assessed, including family poverty-income ratio, marital status, education, employment, food security, healthcare access, insurance type, and housing status. Survey-weighted logistic regression was used to examine individual associations, and weighted quantile sum (WQS) regression was applied to evaluate the overall mixture effect of SDoH. Results The weighted prevalence of epilepsy was 1.1%. In fully adjusted models, unemployment, unmarried status, very low food security, lack of routine healthcare access, and government insurance were significantly associated with epilepsy. In WQS analysis, the overall SDoH index was associated with a threefold increase in epilepsy odds (OR 3.03, 95% CI 1.85–4.95, p < 0.001). Among individual components, food security contributed the most to the mixture effect (weight = 0.39), followed by family poverty-income ratio (weight = 0.19). These findings were generally consistent across subgroup analyses. Conclusions Adverse social determinants of health were collectively associated with higher odds of epilepsy, with food insecurity and low income playing dominant roles. These findings highlight the importance of addressing social and economic disparities in epilepsy prevention and management.