A Systematic Review of the Risk of Motor Vehicle Collision in Patients With Syncope

Background: Drivers at risk of sudden incapacitation from syncope pose a potential threat to themselves and to society. The purpose of this systematic review is to synthesize the risk of motor vehicle collisions (MVCs) for patients with a history of syncope. Methods: We systematically searched Medline (1946-2019) as well as Cinahl, Embase, Psychinfo, and the Transportation Research Information Documentation (1806-2017) for articles on MVCs and drivers with vasovagal syncope (WS), arrhythmic syncope, or syncope not yet diagnosed (NYD). Quality ratings were assigned by team consensus. Results: Eleven studies of moderate quality were included (n = 42,972). Compared with the general populations of Canada, the United States, and the United Kingdom (0.49%-2.29% per driver-year), the prospective MVC risk was lower for WS (0.0%-0.31% per driveryear; 3 studies; n = 782) and higher for arrhythmic syncope (1.9%3.4% per driver-year; 2 studies; n = 730). The results were more variable for syncope NYD (0.0%-6.9% per driver-year prospectively; 6 studies; n = 41,460). Patients with syncope NYD had an almost 2-fold increased MVC risk in the largest study, although the smaller studies showed contradictory findings. Conclusions: WS patients appear to be at very low risk for MVCs, supporting current guidelines which do not recommend driving suspension for these patients in most cases. Although the data for other forms of syncope are too limited for definitive conclusions and must be improved, arrhythmic syncope appears to be associated with nontrivial risk.