People with epilepsy appear to have a much higher risk of drowning compared to people without epilepsy, according to a study published in the August 19, 2008, issue of Neurology.

Previous studies have shown a higher risk most likely due to seizures but this study is one of the first to show exactly how high the risk may be.

For the study, researchers compiled information from 50 studies of people with epilepsy worldwide that followed the participants for a total of more than 200,000 patient-years. They also looked at population data and national registries to determine how many regular drowning deaths occur. A total of 88 people with epilepsy died by drowning. By comparison, 4.7 deaths by drowning would have been expected if the rates in the general population applied.

The study found that people with epilepsy had a 15 to 19 times higher risk of drowning compared with people in the general population. That risk was highest for people with epilepsy and a learning disability, those in institutional care and those who have had brain surgery but who were not all free of seizures.

“It is important that people with epilepsy and their caregivers take steps to prevent these tragedies,” said study author Ley Sander, MD, FRCP, PhD, of the University College London Institute of Neurology, Queen Square in London, UK, and member of the American Academy of Neurology.

“People with active epilepsy should shower instead of bathe, take medication regularly to control seizures and should have direct supervision when swimming,” Sander said.

The study also found that the increased risk of drowning may not be as great in children compared with adults. Sander explains it is most likely a result of more direct supervision.

The Global Burden of Disease 2000 Project estimates that nearly 450,000 people drowned in 2000 worldwide, putting the normal drowning risk at about 7 deaths per 100,000 people.

The study was supported by the UK National Society for Epilepsy and by the UCLH/UCL Comprehensive Biomedical Research, which received funding from the NHS National Institute for Health Research.