Odds ratios of various driving related events – categorical variables. Abbreviations: MBA – motor bike accident; MVA – motor vehicle accident; BZD – benzodiazepines; FX – effects. Note that the numerators for ran away from crash and anybody killed have been adjusted as described to allow calculation of an odds ratio, as the numbers identified in the N-SUD group were zero. Note the scale break. * – P < 0.05. ** – P < 0.01. *** – P < 0.001. **** – P < 0.0001.