Prevalence of epilepsy among people with intellectual disabilities: A systematic review

Purpose: Epilepsy is more common in people with intellectual disabilities than in the general population. However, reported prevalence rates vary widely between studies. This systematic review aimed to provide a summary of prevalence studies and estimates of prevalence based on meta-analyses. Method: Studies were identified via electronic searches using Medline, Cinahl and PsycINFO and cross-citations. Information extracted from studies was tabulated. Prevalence rate estimates were pooled using random effects meta-analyses and subgroup analyses were conducted. Results: A total of 48 studies were included in the tabulation and 46 studies were included in meta-analyses. In general samples of people with intellectual disabilities, the pooled estimate from 38 studies was 22.2% (95% CI 19.6-25.1). Prevalence increased with increasing level of intellectual disability. For samples of people with Down syndrome, the pooled estimate from data in 13 studies was 12.4% (95% CI 9.1-16.7), decreasing to 10.3% (95% CI 8.4-12.6) following removal of two studies focusing on older people. Prevalence increased with age in people with Down syndrome and was particularly prevalent in those with Alzheimer's/dementia. Conclusion: Epilepsy is highly prevalent in people with intellectual disabilities. Services must be equipped with the skills and information needed to manage this condition. (C) 2015 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.