Family income and epilepsy prevalence in the United States: Insights from the National Health Interview Survey

To investigate the association between family income and the prevalence of epilepsy in a representative sample of U.S. adults. We used data from the 2022 National Health Interview Survey (NHIS). The primary exposure variable was the poverty ratio (family income/federal poverty level) which was categorized into four groups: ≤1.00, 1.01-1.99, 2.00-3.99, and ≥4.00. The prevalence of epilepsy was the main outcome measure. We employed log-binomial regression models to estimate prevalence ratios (PRs) and 95% confidence intervals (CIs) for the association between poverty ratio and epilepsy, adjusting for potential confounders. Analyses were stratified by sex and smoking status to explore potential effect modification. The study sample included 26,258 adults, with a mean age of 53.1 years. In both unadjusted and adjusted log-binomial regression models, there was an inverse association between family income and epilepsy prevalence. Compared to individuals within the lowest poverty ratio category (≤1.00), those with poverty ratios of 1.01-1.99 had a PR of 0.68 (95% CI: 0.50, 0.93). Participants with poverty ratios of 2.00-3.99 and ≥4.00 had further reduced PRs of 0.55 (95% CI: 0.40, 0.77) and 0.37 (95% CI: 0.25, 0.54), respectively. This inverse relationship was particularly pronounced among current and former smokers. Our findings suggest that lower family income is independently associated with a higher prevalence of epilepsy among U.S. adults. The observed association underscores the importance of socioeconomic factors in the epidemiology of epilepsy. Additionally, addressing smoking behaviors in low-income populations may be crucial in mitigating health disparities related to epilepsy.