History of Fainting Raises Risk of Motor Vehicle Accidents

MedicalResearch.com Interview with:
Anna-Karin Numé MD, PhD student
Copenhagen University Gentofte Hospital
Department of Cardiology
Cardiovascular Research
Hellerup Denmark 

Medical Research: What is the background for this study?

Dr. Numé: While it is obvious that a loss of consciousness while driving a car is very dangerous, what is not known is whether individuals who have had an episode of fainting (syncope) have a significantly higher risk of having car crashes in the future. Because about one third of patients with syncope are likely to have a recurrence, physicians face a difficult judgment about whether patients with syncope are fit to drive.

Medical Research: What are the main findings?

Dr. Numé: In this nationwide study of patients with syncope, having a history of syncope were associated with a 2-fold-higher risk of later motor vehicle crashes requiring medical attention at an emergency department or hospital compared with the general population – a risk that remained elevated throughout a follow-up of 5 years. This risk was small in absolute terms, yet raises important questions about policies towards driving.

Medical Research: What should clinicians and patients take away from your report?

Dr. Numé: Clinical guidelines for doctors to manage patients with syncope are being updated, and the results of this study are being reviewed as part of a comprehensive review of driving recommendations for patients with syncope. This is one particular instance of drivers who develop medical conditions that could affect their driving ability, and there are tradeoffs between restrictions on driving and the ability of the patients to work, shop, etc.

Medical Research: What recommendations do you have for future research as a result of this study?

Dr. Numé: Further examination of why this association between syncope and motor vehicle crashes occurs.


Numé A, Gislason G, Christiansen CB, et al. Syncope and Motor Vehicle Crash Risk: A Danish Nationwide Study. JAMA Intern Med.Published online February 29, 2016. doi:10.1001/jamainternmed.2015.8606.

Anna-Karin Numé MD, PhD student (2016). History of Fainting Raises Risk of Motor Vehicle Accidents