Objectives: MHE patients have impairment on driving tests. However, it is unclear whether this impairment is restricted to the testing environment or is associated with increased traffic violations and/or motor vehicle accidents.
Methods: An anonymous driving history and driving behavior questionnaire (DBQ: self-scored, best score 104), coded according to MHE status, was sent to 200 cirrhotics without overt hepatic encephalopathy and 100 age/education-matched controls. The questionnaire inquired about demographics, alcohol/illegal drug use, and violations/accidents within 1 and 5 yr. The cirrhotics had been divided into those with MHE (MHE+), without MHE (MHE-), and those not tested for MHE because of psychoactive drug use, on a previous study.
Results: Cirrhotics versus controls had similar driving duration, alcohol/illegal drug use but significantly higher percentage with violations within both 1 and 5 yr (25%vs 4%[5 yr]), 13%vs 2%[(1 yr]), accidents (17%vs 4%[5 yr]), 9%vs 1%[1 yr]), and both (34%vs 7%[5 yr], 18%vs 3%[1 yr]). MHE+ cirrhotics had significantly higher percentage with violations (36%[5 yr], 21%[1 yr]), accidents (33%[5 yr]), 17%[1 yr]), and both (53%[5 yr], 33%[1 yr]) versus other cirrhotics. DBQ score was significantly lower in cirrhotics than controls (92 vs 99). Within cirrhotics, DBQ score was highest in MHE-versus other groups. MHE+ status was the only risk factor (odds ratios: 4.2-7.6) for violations and for accidents on multivariate logistic regression.
Conclusions: Cirrhotics have a higher self-reported occurrence of violations and accidents compared to controls. MHE+ a is strong predictor for violations and accidents. Prospective studies investigating the effect of MHE treatment on violations and accidents are warranted.