Seasonal and Time-Trend Variation by Gender of Alcohol-Impaired Drivers at Preventive Sobriety Checkpoints

Abstract

Objective: We aim to analyse time evolution and seasonality of the outcomes of non-random alcohol concentration breath tests performed on drivers at sobriety checkpoints in Catalonia (Spain) from 2005 to 2012. Differences by gender are also explored.Methods: Time series analyses of the monthly prevalence of drunk drivers by gender. The sample consisted of all drivers tested at non-random sobriety checkpoints in Catalonia (Spain) from 2005 to 2012 (n=3,985,000). Our outcome variable was the monthly prevalence of drivers with a breath alcohol concentration at or above the legal limit. The driver's gender was also registered.Results: A decreasing trend in drunk-driving over time was found, the gender gap diminished after 2008 and disappeared in 2012. After adjusting for trend, the monthly coefficient presented the lowest value for males in January at 3.91% (p<0.001) and the highest in July at 4.72% (p<0.001) and September at 4.75% (p<0.001). The monthly coefficient was lowest for females in January at 3.05% (p<0.001) and highest in October at 4.12% (p <0.001). After seasonal the lowest coefficient is found in winter both for men and women. Conclusion:Seasonal patterns for male and female drivers testing positive at preventive nonrandom sobriety checkpoints indicate that the prevalence of drunk-driving peaks in spring for males and in autumn for females. We recommend that the authorities enforce campaigns that target male and female drinkers differently.

Prevalence of drug use among drivers based on mandatory, random tests in a roadside survey

“…For example, no time data were available, so trends over time could not be studied. Data were collected in autumn, following the alcohol-use seasonality pattern presented by drivers on Catalan roads [ 28 ]. However, drug-use seasonality may differ, which means our results might only reflect drug prevalence in autumn.…”

“…The fieldwork was conducted in the autumn of 2014. In Catalonia, spring and autumn are associated with intermediate rates of alcohol-impaired driving, whereas high peaks are typically observed in summer and significantly lower levels are found in winter [ 28 ]. The sample was collected over a month and a half, between October 1 and November 16.…”