Awareness of legal blood alcohol concentration limits amongst respondents of a national roadside survey for alcohol and traffic behaviours in Brazil.

BACKGROUND In Brazil the legal blood alcohol content (BAC) allowed for driving was changed to zero in 2008. If the BAC found is above 0.6g/L, drivers may be arrested. However, there are limited data on drivers' awareness of such limits. METHODS Drivers from 27 major metropolitan areas (n=3397) were randomly asked to participate in roadside survey from 12 a.m. to 12 p.m. on Fridays and Saturdays. They were breathalized by highway patrol officers, and after consent interviewers collected data on drinking behaviours, knowledge about the law, and breath tests results. RESULTS The mean age was 37.3±11.3 years; 94.3% were male and 26.5% had some college education. When asked about the BAC that could result in arrest, 34.5% of the subjects claimed to know it. However, only 23.5% (8.1% of the total sample) provided correct answers. Factors associated with the right answers were: male gender (p=0.04; OR=2.08; CI=1.01-4.27); higher education (p<0.0001); negative BAC or self-report of driving under the influence (DUI) (p=0.02); higher family income (p=0.01) and non-professional driving (p=0.041). Age was not statistically different between groups. After multivariate analysis, male gender (p=0.002), higher education (p<0.0001) and negative BAC or DUI (p=0.046) remained in the model. CONCLUSIONS The knowledge that BAC levels over 0.6g/L may result in arrest is sparse amongst Brazilian drivers, notably amongst women, the less educated and those who drink and drive. Educational programmes targeted at those specific groups may be necessary in order to increase awareness about the legal BAC limit and its consequences.