Does diabetes affect the risk of involvement in a motor vehicle crash?

Objectives: To systematically review the literature examining the motor vehicle crash risk for drivers with diabetes and quantify any impacts on on-road driving performance. Methods: This systematic review was registered with PROSPERO (see CRD42020158294). A systematic search of public health, psychology and transport databases was conducted in November 2019. The quality of evidence for each study was rated using the National Heart, Lung and Blood Institute Quality Assessment tools. Results: Seven studies published between 1961 and 2019 met the inclusion criteria (case-control = 2; cohort/cross-sectional = 5). Five studies reported evidence for an increased crash risk. The more recent studies reported statistically non-significant crash risks for non-commercial drivers only slightly higher than that of the comparison groups of drivers with no medical conditions known to influence fitness-to-drive while similar comparisons for commercial drivers showed a moderate increase in crash risk. The differences between crash risks for drivers with diabetes treated with insulin and those treated with oral hypoglycemic medications also diminished over time. No studies investigated the effects of diabetes on on-road driving performance. Conclusions: There is evidence for the maintenance of current medical standards for drivers with diabetes although consideration should be given to eliminating distinctions between those using insulin and those on other drugs.