BENZODIAZEPINE USE AND MOTOR-VEHICLE ACCIDENTS - SYSTEMATIC REVIEW OFREPORTED ASSOCIATION

OBJECTIVE To examine the relationship between benzodiazepine (BZD) use and motor vehicle accidents (MVAs). DATA SOURCES MEDLINE was searched from 1980 to 1997 using the kev words traffic accidents or motor vehi cle accidents and benzodiazepines (and alternative terms and outcomes) in English, German, French, or Italian. STUDY SELECTION Case-control studies of BZDs and MVAs; police or emergency studies of BZD use among travelers; driving tests with subjects taking BZDs. Outcomes were imp aired driving, accidents; mortality; postaccident medical attention, e mergency ward care, or hospitalization. Quality criteria were whether all driving BZD users and non-users had an equal chance of entering th e study; whether medication dosage and timing were ascertained; whethe r all kilometres driven by BZD users and non-users were studied; wheth er all types of accidents were ascertained; and whether medical condit ions were controlled for. SYNTHESIS In case-control studies, the odds ratios for mortality and emergency medical treatment ranged from 1.45 to 2.4 in relation to time of use and quantity of drug taken. In polic e and emergency ward studies, BZD use was a factor in 1% to 65% of acc idents (usually 5% to 10%). In two studies where subjects had blood al cohol concentrations less than the legal limit, BZDs were found in 43% and 65% of subjects. In one study with controls, 5% of drivers and 2% of controls in accidents had used BZDs. CONCLUSIONS Case-control stud ies suggest using BZDs approximately doubles the risk of motor vehicle accidents. The risk for drivers older than 65 of being involved in re ported motor vehicle collisions is higher when they take longer-acting and larger quantities of BZDs.