Does Chronic Kidney Disease-Induced Cognitive Impairment Affect Driving Safety?

PURPOSE OF REVIEW

One of the principal mechanisms by which illness can affect driving safety is by impairing cognition. Nevertheless, despite the substantial evidence demonstrating cognitive impairment in chronic kidney disease (CKD), little is known about the effects of CKD on driving safety.

OBJECTIVE

Investigate the current national medical guidelines and research literature with respect to CKD and driving safety.

SOURCES OF INFORMATION

Medline, CINAHL, PEDro, Scopus as of August 2017. The most up to date national driving guidelines and available information provided by the provincial and territorial ministries of transportation across Canada.

FINDINGS

Fives studies of driving fitness in patients with CKD have been published with minimal data available for patients at early stages of the disease. Amongst these studies, only two come from an era when modern end stage renal disease therapies were routinely provided. The first study demonstrated that 40% of 186 surveyed patients on hemodialysis felt uncomfortable driving and that 1/3 of patients were involved in motor vehicle collisions (MVC) since starting dialysis. Of the patients who felt comfortable driving, more than 75% were found to be at increased driving risk. The second study reported that 15% of patients on hemodialysis were involved in MVCs over a three year span and that the "Am I A Safe Driver" assessment tool by the American Medical Association may not capture all patients at high driving risk. Despite these alarming numbers, national guidelines place few driving restrictions on this patient population and only 3 of 11 available provincial or territorial driving forms include kidney disease as a category that physicians should consider when assessing medical fitness to drive.

LIMITATIONS

Our review is limited by the lack of randomized control studies evaluating the effects of CKD on driving safety.

IMPLICATIONS

Our review demonstrates that driving safety in this patient population remains poorly understood. The limited evidence that does exist, however, suggests that these patients are at substantial risk for unsafe driving. Future research is necessary to determine the impact of CKD-associated cognitive impairment on driving risk, and to parse out the contributions of CKD and its various treatments to driving impairment.