From phone use to speeding and driving under influence: Identifying clusters of driving risk behaviors as an opportunity for targeted interventions

Identifying the profile of risky behaviors among drivers is central to propose effective interventions. Due to the multidimensional and overlapping aspects of risky driving behaviors, cluster analysis can provide additional insights in order to identify specific subgroups of risk. This study aimed to identify clusters of driving risk behavior (DRB) among car drivers, and to verify intra-cluster differences concerning clinical and sociodemographic variables. We approached a total of 12,231 drivers and we included 6392 car drivers. A cluster algorithm was used to identify groups of car drivers in relation to the DRB: driving without a seat belt (SB), exceeding the speed limit (SPD), using a cell phone while driving (CELL), and driving after drinking alcohol (DUI). The algorithm classified drivers within five different DRB profiles. In cluster 1 (20.1%), subjects with a history of CELL. In cluster 2 (41.4%), drivers presented no DRB. In cluster 3 (9.3%), all drivers presented SPD. In cluster 4 (12.5%), drivers presented all DRB. In cluster 5 (16.6%), all drivers presented DUI. Clusters with DUI-related offenses (4 and 5) comprised more men (81.9 and 78.8%, respectively) than the overall sample (63.4%), with more binge drinking (50.9 and 45.7%) and drug use in the previous year (13.5 and 8.6%). Cluster 1 had a high years of education (14.4 ± 3.4) and the highest personal income (Md = 3000 IQR [2000-5000]). Cluster 2 had older drivers (46.6 ± 15), and fewer bingers (10.9%). Cluster 4 had the youngest drivers (34.4 ± 11.4) of all groups. Besides reinforcing previous literature data, our study identified five unprecedented clusters with different profiles of drivers regarding DRB. We identified an original and heterogeneous group of drivers with only CELL misuse, as well as other significant differences among clusters. Hence, our findings show that targeted interventions must be developed for each subgroup in order to effectively produce safe behavior in traffic.

Hip-flask defense: An experimental study in the Hungarian population

Toxicology tests and medical expert opinions are part of routine work in drunk driving cases in both domestic and international practice. The greatest challenge to forming an opinion is that the perpetrator claims to have consumed alcohol after the act of driving. To determine the time of consumption, it is essential to establish whether the alcohol in the body was in the absorption phase or in the elimination phase when the sample was collected. In domestic practice, breath alcohol content can be measured several times, two blood samples can be collected, and both blood and urine samples can be taken almost simultaneously. A recent Swedish study showed that taking a single blood sample and two urine samples allows for a more accurate examination of consumption after the fact. This study aimed to examine the applicability of such model to the domestic environment. We conducted a controlled drinking experiment involving 15 Hungarian casual drinker volunteers aged 18-25 years who consumed different amounts of alcohol at specified times while providing regular breath alcohol measurements as well as blood and urine samples. These measurement results provided accurate information about the changes in alcohol metabolism compared to the time of drinking and allowed us to draw the necessary conclusions, offering further evidence that alcohol metabolism can vary significantly between different ethnic groups. The results showed that the absorption and excretion of ethyl alcohol in the volunteers were much faster than those in the current Hungarian standards used in practice. In conclusion, the comparison of blood and urine samples collected between 60 min and 120 min cannot be considered suitable for establishing the fact of drinking after driving in Hungarian practice, and a local model is needed.

Toxicological oral fluid results among Spanish drivers testing positive on on-site drug controls from 2013 to 2015

BACKGROUND

Driving under the influence of drugs (DUID) increases the risk of serious injury or death in traffic accidents. The aim of this study was to provide information about DUID in Spanish drivers.

METHODS

10,064 oral fluid samples were collected from Spanish drivers that tested positive on the roadside using the Dräger DrugTest 5000 (DDT5000) between 2013 and 2015. Samples were collected using Quantisal^™ and analysed by LC-MS/MS at the Toxicology Laboratory of the Institute of Forensic Science of the University of Santiago de Compostela.

RESULTS

Drivers were mainly young men (85.1% male, 29.7 ± 8.1 years old). In 98.5% of cases, LC-MS/MS results confirmed at least one of the positive results detected on the roadside. Cannabis (82.4%) and cocaine (42.1%) were the most commonly detected drugs. Poly-drug use was observed in 42.7% of drivers, mostly for all illicit drugs (>80%) except for cannabis (42.6%). Illicit drug and single-drug use was more frequent among drivers under 35 years old, and medicines and poly-drug use more common among drivers older than 35 years old. The on-site device performance was calculated using both the DDT5000 cut-offs and the LC-MS/MS method LOQs. Sensitivity (>73% vs >58%), specificity [>94% for all the compounds regardless the cut-offs used, except for cannabis (71%)] and accuracy (>87.5% with both cut-offs) fulfilled the DRUID Project requirements in all cases.

CONCLUSION

LC-MS/MS confirmation result was negative in only 1.5% of the cases. The DUID driver profile was a young man, consuming cannabis or a combination of cannabis and cocaine.

Roadside drug testing: comparison of two legal approaches in Belgium

BACKGROUND

Internationally, urine on-site testing has been used for detecting drivers under the influence of drugs (DUID) but more and more countries, such as Belgium, are switching to oral fluid screening.

OBJECTIVE

To compare the previous (published in 1999) and current (published 2009) enforcement procedures of DUID in Belgium. The two evaluated procedures differ in the way the drivers are screened by the police (signs of impairment versus signs of recent drug use), the matrix for screening (urine versus oral fluid) and the analytical cut-off concentrations in plasma.

METHODS

Data on positive screening and confirmation results were gathered from 1st April 2008 to 30th September 2010, when urine screening (Dipro Druglab panels test) was performed; and from 1st October 2010 to 31st March 2013, when an on-site oral fluid test (Securetec Drugwipe 5(+)) was used.

RESULTS

Approximately 4100 data sets related to urine screening and 3900 data sets related to oral fluid screening were studied. Eighty-eight percent of positive urine on-site tests yielded positive results in plasma for cannabis, 21% for cocaine, 20% for amphetamines and 7% for opiates. Sixty-six percent of the positive oral fluid on-site tests yielded positive results in plasma for cannabis, 30% for cocaine, 28% for amphetamines and 8% for opiates. For cannabis, opiates and amphetamines more negative results in plasma were observed in the period of urine screening.

CONCLUSIONS

The percentage of plasma samples of tested drivers, in which none of the positive screened target drugs were present in a concentration above the legal cut-off value, has decreased from 17% to 8% since the introduction of the current legislation involving oral fluid screening.