199984 Estimating epilepsy prevalence: Design, implementation and preliminary results from a population-based survey of Washington, DC residents

Sunday, November 8, 2009

Anne E. Kenyon, MBA , RTI International, Research Triangle Park, NC
Barbara L. Kroner, PhD , RTI International, Rockville, MD
Mansour Fahimi, PhD , Marketing Systems Group, Fort Washington, PA
David J. Thurman, MD, MPH , National Center for Chronic Disease Prevention and Health Promotion, Centers for Disease Control and Prevention, Atlanta, GA
W. Allen Hauser, MD , Professor of Neurology and Epidemiology, Columbia University, New York, NY
William Davis Gaillard, MD , Director, Comprehensive Pediatric Epilepsy Programs, Children's National Medical Center, Washington, DC
Background: Epilepsy affects almost 2% of the U.S. population; however, few studies provide prevalence estimates for low-income and minority populations. Using a multi-mode data collection model, we sought to determine epilepsy prevalence estimates for subgroups in Washington, DC, a racially and socio-economically diverse community.

Methods: Probability-based sampling was used to select 20,000 D.C. addresses. Sample households were asked to complete a screening questionnaire by mail or web, and later by phone, regarding demographics and epilepsy status of each resident. Nonrespondents to the first wave were contacted again and offered an increase in incentive from $1 to $5 to complete the screening.

Results: 6,447 households representing 12,894 individuals (10,753 adults and 2,141 children) responded to the screening questionnaire, a response rate of 34.7% after adjusting for undeliverable mail. Individuals were 39% White, 47% Black, 6% Hispanic, and 8% Other race/ethnicity. 208 (174 adults and 34 children) had a history of epilepsy. While the overall unweighted prevalence of epilepsy was 1.6%, Blacks had a higher prevalence (2.3%) than Whites (1.0%, p<.0001). Prevalence was inversely related to both education and income in total (p<.0001) and in Blacks but not in Whites. Households with epilepsy were more likely to respond overall by phone (5.8%) than by mail or web (2.7%, p<.0001), and in Wave-2 (4.4%) than in Wave-1 (2.7%, p=.0006).

Conclusion: Epilepsy prevalence varies by race, education and income. While the majority of households responded by mail (78%), a multi-pronged approach was required to secure 13% of responses by telephone and 8% by web.

Learning Objectives:
1. Estimate the prevalence of epilepsy among residents of the District of Columbia, particularly among low-income and minority subgroups. 2. Describe implementation of a probability-based sampling and multi-mode survey approach.

Presenting author's disclosure statement:

Qualified on the content I am responsible for because: I was the survey director of the project and led the data collection activities.
Any relevant financial relationships? No

I agree to comply with the American Public Health Association Conflict of Interest and Commercial Support Guidelines, and to disclose to the participants any off-label or experimental uses of a commercial product or service discussed in my presentation.