Abstracts

Rationale: A strong link between epilepsy and low socioeconomic status has been well documented. Our recent analysis demonstrate that the incidence and prevalence of epilepsy among adult Medicaid beneficiaries, most of whom are educationally and socioeconomically disadvantaged, were higher than that reported in the general population. Whether low-income children have high incidence and prevalence of epilepsy remains largely unknown. No study, to our knowledge, has specifically examined the incidence and/or prevalence of epilepsy in this subpopulation. This study was designed to estimate the incidence and prevalence of epilepsy in low-income children who participate in the Medicaid program. Methods: We performed a retrospective cohort study using the Medicaid Analytic Extract (MAX) data between 2005 and 2008 for Ohio, Illinois, Florida and California. Beneficiaries who were younger than 18 years of age were included in our analysis. Beneficiaries who enrolled in managed care plan, or had dual insurance were excluded. Beneficiaries were identified as cases if they had ≥2 claims of epilepsy (ICD-9-CM: 345.xx) or ≥3 claims of convulsion (ICD-9-CM: 780.3 or 780.39), and ≥2 claims of antiepileptic drugs. The date of first diagnosis of epilepsy or the second diagnosis of a non-febrile convulsion that appeared at least 24 hours from the first convulsion was defined as the date of epilepsy onset or index date. Only beneficiaries who were born in 2005 were included for incidence estimates. Incident cases were required to have no epilepsy or convulsion claims before epilepsy diagnosis. Results: There were 27,761 prevalent and 979 incident cases of epilepsy. The overall prevalence was 3.79 per 1,000 (95% CI: 3.78-3.80). The three year cumulative incidence was 2.94 per 1,000 (95% CI: 2.80-3.10). The prevalence of epilepsy was highest in children aged 10-14 years. Boys had higher incidence and prevalence of epilepsy than girls. Interestingly, there were regional variations of incidence and prevalence of epilepsy. Medicaid children in Ohio had the highest incidence and prevalence of epilepsy compared to those in Florida, Illinois, and California. White Medicaid children in Florida had greater incidence and prevalence of epilepsy than blacks and Hispanics. White Medicaid children in Ohio also had higher prevalence of epilepsy but the incidence was lower than that of Hispanics. In Illinois and California, black children had greatest prevalence and incidence of epilepsy compared to other races. All statistics are shown in table1. Conclusions: The overall incidence and prevalence of epilepsy in Medicaid children were lower than those reported in the general population. Since there are regional differences of incidence and prevalence of epilepsy, the incidence and prevalence estimates that are specific for the region of interest are crucial for complete understanding of the burden of epilepsy and resource allocation to that area.