self-reporting, estimated 8.4/1,000 cases of active epilepsy2 (Kobau et al., 2008). If lifetime prevalence (i.e., ever having epilepsy) is considered, the BRFSS estimate increases to 16.5/1,000 (1.7 percent of respondents) (Kobau et al., 2008).
More studies have been done on the prevalence of epilepsy than on its incidence because prevalence studies are easier and faster to conduct. Prevalence data are used to inform planning for resources and services to meet the health care and social needs of people with epilepsy. To obtain a complete picture of epilepsy, prevalence studies should be conducted using the same data sources as those in which long-term studies of epilepsy incidence are conducted. Socioeconomic status (SES) and race/ethnicity are discussed below as examples of two areas in which further research on incidence and prevalence is needed.
Socioeconomic status Low SES is associated with a higher incidence of epilepsy (Heaney et al., 2002). Hesdorffer and colleagues (2005) studied adults in Iceland and found that people with epilepsy are more likely to have low SES in comparison to age- and gender-matched controls without epilepsy. This association exists in a society with universal health care where everyone has health insurance, and it also persists in adults with epilepsy of unknown etiology, even after adjustment for cumulative alcohol consumption, which could be a confounding factor. Furthermore, low SES is also associated with an increased prevalence of epilepsy (Morgan et al., 2000; Shamansky and Glaser, 1979). Reasons for this are not well understood because these studies did not distinguish between epilepsy of unknown etiology and epilepsy of known etiology, which is problematic because some known etiologies of epilepsy (e.g., TBI, stroke) may themselves be associated with low SES (Chang et al., 2002; Cubbin et al., 2000). While associations between SES and the etiology of epilepsy is one possible explanation for the association between SES and prevalence, existing treatment gaps may play a role as well, since people of lower SES are less likely to obtain seizure medications or to be under the care of a neurologist than people of higher SES (Begley et al., 2009), making them more likely to experience persistent seizures (Chapter 4).
Race/ethnicity A study in the Harlem neighborhood of New York City found epilepsy prevalence to be higher in Hispanics than in non-Hispanics
2Defined as “a history of epilepsy and currently taking medication or reporting one or more seizures during the past 3 months” (Kobau et al., 2008, p. 1).