Minimal hepatic encephalopathy: a vehicle for accidents and traffic violations

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.

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.

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.

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.