National and regional prevalence of self-reported epilepsy in Canada

Abstract

Purpose: To assess the point prevalence of self-described epilepsy in the general population nationally, provincially, and in different groups of interest.

Methods: We analyzed data from two national health surveys, the National Population Health Survey (NPHS, N=49,000) and the Community Health Survey (CHS, N=130,882). Both surveys captured sociodemographic information, as well as age, sex, education, ethnicity, household income, and labor force status of participants. Epilepsy was ascertained with only one question in both surveys. "Do you have epilepsy diagnosed by a health professional?" (NPHS) and "Do you have epilepsy?" (CHS). Prevalences were age-adjusted by using national standard populations at the time of each survey. Exact 95% confidence intervals were obtained.

Results: In the NPHS, 241 of 49,026 subjects described themselves as having been diagnosed with epilepsy, yielding a weighted point prevalence of 5.2 per 1,000 [95% confidence interval (CI), 4.9-5.4]. In the CHS, 835 of 130,822 subjects described themselves as having epilepsy, yielding a weighted point prevalence of 5.6 per 1,000 (95% CI, 5.1-6.0). Trends in differences in prevalence among some Canadian provinces were observed. Prevalence was statistically significantly higher in groups with the lowest educational level, lowest income, and in those unemployed in the previous year. Prevalence also was higher in nonimmigrants than in immigrants.

Conclusions: The overall and group-specific results are in keeping with those obtained in other developed countries by using different ascertainment methods. We discuss methodologic aspects related to the ascertainment of epilepsy in both surveys, and to the validity and implications of our findings.