2010 BC Guide in Determining Fitness to Drive

14.3 Chronic renal disease and adverse driving outcomesThe evidence linking chronic renal disease with adverse driving outcomes is weak because therehas been limited research in this area and the research that is available is either dated or hasmethodological limitations.14.4 Effect of chronic renal disease on functional ability to driveCognitive impairmentEvidence suggests that cognitive impairment is associated with chronic renal disease and thatwith increasing disease severity there is also a corresponding decrease in cognitive functioning,which may impair functional ability to drive.The highest risk of cognitive impairment is for those with ESRD (stage 5). There is a small bodyof literature indicating that ESRD is associated with diminished perceptual motor-coordination,impairments in intellectual functioning including decreased attention and concentration, andmemory impairments. Some studies indicate that individuals with ESRD have a 2 to 7 timeshigher prevalence of cognitive impairment and dementia compared to the general population.There is also evidence of a significant risk of cognitive impairment for those in Stage 3 and 4 ofchronic renal disease. There is no evidence to suggest that risk of cognitive impairment in theearly stages (stage 1 and 2) is significant enough to impair driving.Research indicates that cognitive impairment ranging from mild to severe is common and oftenundiagnosed in dialysis patients. In particular, between 30% and 47% of older patientsundergoing treatment by hemodialysis or peritoneal dialysis were classified as cognitivelyimpaired. In the general population, 8% of Canadians 65 and over have dementia and another17% have some form of cognitive impairment. One study also indicated that physicians had atendency to underestimate cognitive impairment in patients undergoing dialysis.Improvement in cognitive performance has been reported in individuals who have undergone akidney transplant.General debilityIndividuals with chronic renal disease, particularly end-stage renal disease, may develop generaldebility resulting in a loss of stamina required to support the functions necessary for driving.131