Single-vehicle crashes and alcohol: a retrospective study of passenger car fatalities in northern Sweden.

This retrospective study of fatal passenger car crash victims in northern Sweden compares 396 multiple-vehicle (MV) and 201 single-vehicle (SV) fatalities from 1980 through 1989. Compared to MV fatalities, SV victims were more frequently males, were younger, were more often inebriated, had higher blood alcohol concentrations, had a higher frequency of fatty liver, and were less often restrained. The SV fatalities occurred most often from May through October, from Fridays through Sundays, and from 9 p.m. to 6 a.m. The road surface was usually dry, especially for drunken SV drivers. The SV drivers also more often lacked a valid driver's license. The study confirms that alcohol is one of the most important factors associated with traffic fatalities, particularly in SV crashes. More than half (56%) of the SV victims were inebriated by alcohol (MV, 11%), had a mean blood alcohol concentration of 1.9 g/l (MV, 1.6 g/l), and one-third had a fatty liver (MV, 20%). We also found a relation between fatty liver and increased blood alcohol concentrations, suggesting that studies regarding the role of alcohol in traffic fatalities should also include an evaluation of liver morphology.