Drug-impaired Drivers Research Articles

Toxicology findings from drivers suspected of drug-impaired driving in Ontario (2008–2019)

Objective This study examines the results of toxicological tests performed on blood and urine samples collected from suspected drug-impaired drivers in Ontario from 2008 to 2019. The report examines the results of toxicological analysis of the samples submitted, the characteristics of those drivers from whom samples were collected, and the temporal and situational circumstances that led to police investigations and sample collection to better understand drug-impaired driving behavior and to assist in the development and implementation of countermeasure strategies and programs. Methods Blood and urine samples were sent to the Center of Forensic Sciences where they were analyzed using standardized comprehensive toxicological analysis to test for a wide variety of potentially impairing drugs. Demographic and temporal information for each case from which a sample was collected were also examined to describe the circumstances and characteristics of these driving incidents. Results During the 12-year period examined, 5,388 samples collected from suspected drug-impaired drivers were analyzed. The number of samples collected increased substantially following the implementation of the Drug Evaluation and Classification Program (DECP) in July 2008, the enactment of legislation facilitating the collection of blood samples from suspects, and the legalization of cannabis for nonmedical purposes in 2018. The number of samples submitted shows temporal correlation with the number of police officers certified as Drug Recognition Experts (DRE) in the province. Over the 12-year period of this study, cannabis was the most frequently detected substance in drivers (52.8% of cases), followed by cocaine (44.3%) and methamphetamine (24.8%). In 80% of cases, more than one substance was detected. Conclusions Examining the characteristics of suspected drug-impaired drivers, the temporal circumstances, and the drug findings throughout the large geographic area of Ontario and over the extended period of this study enhances our understanding of drug-impaired driving behavior. These characteristics can assist in the development and/or evaluation of enforcement strategies and enhanced countermeasure activities.

Driving under the influence of substances and motor vehicle fatalities among older adults in the United States

Objective This study examines contribution of substance use (including alcohol, cannabinoids, stimulants, narcotics, depressants, and hallucinogens) on the probability of drivers being at-fault for a crash on U.S. public roads, with specific emphasis on older adult drivers. Methods Data from the National Highway Traffic Safety Administration’s Fatality Analysis Reporting System (FARS) for the years 2010–2018 were employed for 87,060 drivers (43,530 two-vehicle crash pairs) involved in two moving vehicle crashes. The quasi-induced exposure (QIE) method was used to compute the relative crash involvement ratios (CIRs) for each relevant substance and illicit drug. Mixed-effect generalized linear regression models were fit to examine the effect of substance use on the probability of a driver being at-fault for a crash. Results There were 75.51% males and 73.88% Non-Hispanic Whites in our sample. The CIR for those aged 70–79 years was 1.17, and more than double (2.56) for the ≥80 years old drivers, while being relatively low among drivers of ages 20 to 69. Substance use, in general, disproportionately increased the probability of being at-fault during a crash, regardless of driver’s age. Though older drivers are less likely than other age groups to report substance use, presence of substances among older drivers increased the probability of their being at-fault two to four times during a crash across almost all substances. The regression models, after adjusting for driver’s sex, road grade, weather, light conditions, distraction, and speeding at time of crash, revealed that older drug-impaired drivers were twice as likely to be at fault in a fatal crash (aOR = 1.947; 95% CI = 1.821, 2.082; <0.0001) compared to their middle-aged counterparts. Similarly, most substance use categories were responsible for the probabilities of higher CIRs among the drivers. Conclusion These findings necessitate continued efforts to bring awareness to the deadly consequences of “drugged driving,” especially among older adult drivers.

Ketamine in DUID cases in the greater Cologne area. A case series

Cases of ketamine consumption in driving under the influence of drugs (DUID) were evaluated with regard to recorded psychomotor impairments and possible co-consumption of drugs of abuse or other substances. Ketamine is a substance that is used e.g. as an anaesthetic or for analgesics in medical treatment. Due to its dissociative effects, ketamine abuse has increased in the past years leading to several drug-impaired driving cases. According to literature, ketamine plasma concentrations above 50 ng/mL are associated with significant psychomotor impairments, whereby mind-altering effects can be expected at plasma concentrations of ketamine between 50 and 200 ng/mL. They seem to be concentration dependent. The most commonly described impairments comprise a slurred speech, drowsiness, confusion and vomiting as well as lack of coordination and dystonia, blurred vision or visual field narrowing, dissociation, referential thinking, euphoria, depersonalization and anxiety. Moreover, pupil dilatation, a lack of convergence, horizontal gaze nystagmus, elevated pulse rate and failure of divided attention tests like walk-and-turn and one-leg stand test were observed. DUID cases from two institutes of legal medicine from the years 2021 to early 2022 were evaluated with regard to drug-impaired drivers who consumed ketamine. The cases were compared with regard to psychomotor impairments, salience in driving and co-consumption of drugs. Technical devices for the analyses of drug concentrations in blood were drug-dependent and therefore either performed by GC-MS/MS, LC-MS/MS or HPLC-DAD. Five cases of drivers (all male, between 21 and 44 years old) were collected. Ketamine consumption was admitted in two out of five cases. Indications for a medical application were not given in the other three cases without confessed consumption. Ketamine concentrations of approx. 165 ng/mL, 245 ng/mL, 610 ng/mL, 676 ng/mL and 3800 ng/mL were detected in the serum samples. Moreover, co-consumption of either one or multiple substances like cannabis ( n = 2), amphetamine ( n = 4), 3,4-methylenedioxymethamphetamine (MDMA) ( n = 1), cocaine ( n = 2) and clonazepam ( n = 1) could be ascertained in all cases. The recorded psychomotor impairments of the drivers comprised e.g. dilated pupils ( n = 2), missing or delayed pupil reactions ( n = 3), as well as aggressive behaviour ( n = 3), a slurred or decelerated speech ( n = 2), a delayed reaction ( n = 2), lack of concentration ( n = 2) or vertigo ( n = 3). The observed psychomotor impairments correlated with literature data. However, the assessment and differentiation of impairments with regard to ketamine consumption is aggravated due to co-consumption of other drugs of abuse or substances. In literature, co-consumption of e.g. alcohol, cannabis, MDMA, amphetamine, benzodiazepines or cocaine is also described when ketamine is abused, which is also in line with the collected data. The extremely high concentration of ketamine (approx. 3800 ng/mL) in one case from the present case series, might allow the supposition that the recorded impairments are most likely due to ketamine consumption, although cocaine and its metabolite benzoylecgonine (BE) were also detected in moderate concentrations (cocaine = 32 ng/mL, BE = 729 ng/mL) as well. However, a decent distinction of the impairments is not possible. The presented case series provides additional data on psychomotor impairments observed in DUID cases after the consumption of ketamine, although the results have to be regarded critically due to co-consumption of other substances and the limited case number. Nevertheless, correlation between existing literature data could be observed. Since the abuse of ketamine has increased in the past years, those data can support the assessment of cases, where ketamine abuse is in question.

Roadside Drug Testing Approaches.

The purpose of this review is to present an overview of roadside drug testing, driving enforcement, and drunk/drug driving detection around the world. Drunk and drug driving is a severe problem, not only in the UAE, but also around the world. This has important implications for road safety as drunk or drug driving may increase the chances of a driver’s involvement in a road crash when compared to a drug-free driver. Recently, due to increases in drug-impaired drivers’ crash involvement, many mobile roadside drug testing devices have been introduced to the market. These devices use oral fluid, urine or blood matrices. These are on-the-spot tests, which are easy to use and are applied by law enforcement agencies and the public. Law enforcement agencies most commonly use oral fluid to detect the presence of illicit drugs in drivers. This review discusses all the available devices in the market used by the authorities. It also describes the type of drugs widely abused by drivers along with behavioral testing methods. The different types of matrices used for roadside drug testing are also evaluated. Sample collection, storage, and pre-treatment methods are discussed, followed by the confirmatory analysis of positive samples. This article will significantly help law enforcement agencies compare and evaluate all the reliable roadside testing devices and new emerging confirmatory devices available to them in the market. This will help them make an informed decision on which device to adapt to their individual needs.

The implementation of per-se limits for driving under the influence of benzodiazepines and related drugs: No increased risk for arrest during therapeutic use in Norway

Objective: To investigate whether the use of recommended therapeutic doses of medicinal drugs has led to suspicion of driving under the influence of drugs (DUID) after implementation of legislative limits for illicit and medicinal drugs in 2012.Methods: Data from suspected drug-impaired drivers apprehended by the police from 2013 to 2015 were selected from the Norwegian Forensic Toxicology Database. The blood samples had been analyzed for benzodiazepines (BZDs), z-hypnotics, opioids, stimulants, certain hallucinogens, and alcohol. Drivers who tested positive for one BZD or a z-hypnotic only, were included in the study. Drug concentrations measured in their blood samples were compared to the maximal obtainable steady state concentrations if the drug had been used in accordance with the recommendations set by the Norwegian Directorate of Health.Results: BZDs or z-hypnotics were found in 10 248 samples, representing 59.6% of the total number of drivers arrested for suspected DUID (n = 17 201). Only one BZD or z-hypnotic with a blood drug concentration above the legislative limit was detected in 390 (2.3%) of the total number of samples. Clonazepam was the most frequently detected BZD (n = 4656), while as a single drug above the legislative limit, it was detected in only 3.6% (n = 168) of the clonazepam-positive blood samples. For drivers testing positive for only one z-hypnotic, drug concentrations above the legislative limit were found in 27% (n = 55) of the blood samples that tested positive for zolpidem and 12.4% (n = 53) of the samples that tested positive for zopiclone. In total, 155 subjects out of 10 248 testing positive for BZDs or z-hypnotics displayed concentrations above the legislative limit but within the concentration ranges that are expected when taking recommended therapeutic drug doses, and 77 below the legislativel limit.Conclusions: The results show that the implementation of legislative limits for BZDs and z-hypnotics may have contributed to DUID suspicion for a small group of patients using therapeutic drug doses; only 1.3% of the suspected DUID offenders had concentrations of only one of those drugs in-line with recommended therapeutic dosing.

Illicit drugs are now more common than alcohol among South Australian crash-involved drivers and riders

Objectives: For a jurisdiction to apply appropriate countermeasures for impaired driving, it is necessary to track drug and alcohol involvement in road crashes. In South Australia, it is mandated that all injured road users aged over 10 who attend a hospital for treatment must have a blood sample taken, which is tested for alcohol and drugs. The drug testing covers the three drugs included in South Australia’s roadside drug testing program: delta-9-tetrahydrocannabinol (THC or cannabis), methamphetamine (‘ice’) and 3,4-methylenedioxymethamphetamine (MDMA or ‘ecstasy’).Methods: The present study involved analysis of the results of drug tests from 2014 to 2017 for road users over the age of 16 at the major trauma hospital in Adelaide, the capital city of South Australia. Comparisons were made to the results of blood tests from an earlier study using data from 2008 to 2010.Results: It was found in the most recent dataset that just over 11 per cent of drivers and just under 5 per cent of motorcyclists had a blood alcohol concentration (BAC) above the legal limit of 0.05 g/100 ml. In regard to the three proscribed drugs, the rates for both drivers and motorcyclists were over 15 per cent. Among drivers, methamphetamine was most common (9.7%), followed by THC (6.3%). Among motorcyclists, THC was most common (9.4%), followed by methamphetamine (6.2%). Inspection of data from 2008 to 2010 reveals that rates of having an illegal BAC when involved in a crash have declined over the past decade (from 20.2% down to 9.3%), while rates of drug use among crash involved drivers and riders have increased (from 10.5% to 15.2%).Conclusions: Although the apparent decline in alcohol involvement in road crashes in recent years in South Australia is to be welcomed, the increasing proportion of road crashes involving drug impaired drivers, particularly those affected by methamphetamine, is cause for concern. A National Drug Driving Working Group has been set up by Austroads to examine improvements in drug driving enforcement practices. The recommendations arising from their work need to be considered for implementation to prevent rising drug driving crashes from replacing the reduction in road crashes attributable to drink driving.

Predicting categories of drugs used by suspected drug-impaired drivers using the Drug Evaluation and Classification Program tests

Objective: The purpose of this study was to statistically determine which combination(s) of drug-related signs and symptoms from the Drug Evaluation and Classification (DEC) protocol best predict the drug category used by the suspected drug-impaired driver.Methods: Data from 1,512 completed DEC evaluations of suspected impaired drivers subsequently found to have ingested central nervous system (CNS) depressants, CNS stimulants, narcotic analgesics, and cannabis were analyzed using a multinomial logistic regression procedure. A set of evaluations completed on drug-free subjects was also included. The relative importance of clinical, behavioral, and observational measures in predicting drug categories responsible for impairment was also examined.Results: Thirteen drug-related indicators were found to significantly contribute to the prediction of drug category, including being under the care of a doctor or dentist, condition of the eyes, condition of the eyelids, mean pulse rate, assessment of horizontal gaze nystagmus (HGN), convergence, performance on the One Leg Stand (OLS) Test, eyelid tremors, pupil size in darkness, reaction to light, presence of visible injection sites, systolic blood pressure, and muscle tone. Indicators related to the appearance and physiological response of the eye contributed the most to the prediction of drug category, followed closely by clinical indicators and performance on the psychophysical tests.Conclusions: The findings from this study suggest that drug recognition experts (DREs) should be careful to review a set of key signs and symptoms when determining the category of drug used by suspected drug-impaired drivers. Drug use indicators related to the appearance and physiological response of the eye were found to contribute the most to the prediction of the drug category responsible for the impairment. These results could help form the basis of a core set of indicators that DREs could initially consult to form their opinion of drug influence. This in turn may enhance the validity, effectiveness, and efficiency of drug detection and identification by DREs and lead to a more effective and efficient DEC program, improved enforcement of drug-impaired driving, and greater acceptance of the DEC program by the courts.

Characteristics of Prescription-Opioid-Impaired and Other Substance-Impaired Drivers in Rural Appalachian Kentucky

ABSTRACTPrevious studies have highlighted the prescription opioid epidemic in rural Appalachia and its associated risk behaviors; however, no studies have examined prescription-opioid-impaired driving as a consequence of this epidemic. The purpose of the present study was to describe prescription-opioid-impaired drivers in rural Appalachian Kentucky and examine how they are similar to and different from other substance-impaired drivers from the region. A sample of convicted DUI offenders from rural Appalachian Kentucky completed a confidential research interview focused on their substance use, mental health, and criminal activity. Prescription-opioid-impaired drivers (n = 33) were compared to other drug-impaired drivers (n = 29) and to alcohol-only-impaired drivers (n = 44). Overall, prescription-opioid-impaired drivers had a similar prevalence of illicit substance use and criminal activity, including impaired driving frequency, to other drug-impaired drivers, but had a higher prevalence of illicit substance use and more frequent impaired driving when compared to alcohol-only-impaired drivers. Study implications include the importance of comprehensive substance abuse assessment and treatment for DUI offenders and the need for tailored interventions for prescription-opioid-impaired and other drug-impaired drivers.

Evaluation of Dräger DrugTest 5000 in a Naturalistic Setting.

Reliable field testing devices for psychoactive drugs would be useful tools for the police for detecting drug-impaired drivers. The Norwegian Mobile Police Service (NMPS) started using Dräger DrugTest 5000 (DDT5000) in 2015 as an on-site screening instrument for drugs in samples of oral fluid. The aim of this study was to compare the results of field testing of DDT5000 with drug findings in blood and oral fluid samples taken from drivers suspected for driving under the influence of drugs (DUID). In total, 369 drivers were included in this field testing; blood samples were obtained from all of them, while oral fluid samples were collected with the Intercept device from 301 of them. The median time from field testing with DDT5000 and collection of blood and oral fluid samples was 50 min. The proportions of false positive results with DDT5000 compared to findings in blood samples above the Norwegian legal per se limits were for cannabis 14.5%, amphetamine 23.2%, methamphetamine 38.4%, cocaine 87.1%, opiates 65.9% and benzodiazepines 36.4%. The proportions of false negatives were for cannabis 13.4%, amphetamine 4.9%, methamphetamine 6.1%, cocaine 0.0%, opiates 0.0% and benzodiazepines 18.8%. Among drivers who had drug concentrations above the legal limits in blood, the proportion who tested positive using DDT5000 was 82.9% for THC, 90.8% for amphetamine, 75.7% for methamphetamine, 100.0% for cocaine, 100.0% for opiates and 37.2% for benzodiazepines. In cases with false-positive DDT5000 results compared to blood, traces of drugs were most often found in oral fluid. The DDT5000 did not absolutely correctly identify DUID offenders due to fairly large proportions of false-positive or false-negative results compared to drug concentrations in blood. The police reported that DDT5000 was still a valuable tool in identifying possible DUID offenders, resulting in more than doubling the number of apprehended DUID offenders.

Toxicological findings in suspected drug-impaired drivers in Norway — Trends during 1990–2015

This study describes trends in drug use among drivers suspected of driving under the influence of drugs, apprehended by the police in Norway during 1990–2015. Chromatographically determined toxicological findings in blood samples were retrospectively investigated. Drug findings above defined cut-off concentrations were considered positive; hence making the annual prevalence comparable during the 26 years studied.Blood samples from 112,348 drivers were included, of which 63% were positive for drugs; 43% had combined drug with alcohol or other drugs. In total, 87% of the drug-positive drivers were men, and a higher proportion of them were positive for illicit drugs compared to the women. Benzodiazepines and related drugs were found in 57% of the drug-positive drivers, stimulants in 51%, cannabis (tetrahydrocannabinol, THC) in 34%, and opioids in 18%. The types of benzodiazepines and opioids changed over time. The age distribution also changed; the proportion of drug-positive drivers above 40 years of age increased for all drug classes. The annual number of suspected drug-impaired drivers increased by 122% from 1990 to 1999, and by 54% from 2000 to 2015; the annual number of drug-positive samples increased by 260% from 1990 to 1999, and by 60% from 2000 to 2015. During 2000–2015, an increasing prevalence of amphetamines was found among suspected drug-impaired drivers above age 30; the highest rate of increase was observed among those at or above age 40. In the same period, the prevalence of benzodiazepines and related drugs decreased among all age groups, whereas the prevalence of THC increased; the highest prevalence and rate of increase were among suspected drug-impaired drivers under the age of 30. The results from this study indicate a slight change in the types of drugs used by drivers in Norway.

Increasing use of cannabis among arrested drivers in Norway

ABSTRACTObjective: The availability of cannabis in Norway seems to have increased according to seizures by customs and police. On the other hand, national population surveys have not found any increase in self-reported use of cannabis. This investigation aimed at studying trends in cannabis use among suspected drug-impaired drivers apprehended by the police in Norway.Methods: A time series observational study of cannabis use among all drivers tested for drugs during 2000–2015 was performed. Descriptive analyses of trends in frequencies and combined use of cannabis with other drugs or alcohol for different age groups and gender were conducted.Results: Tetrahydrocannabinol (THC) is the main psychoactive substance in cannabis and was detected in blood samples from 18,767 suspected drug-impaired drivers. The annual number of THC findings increased during the years 2000–2015 for all age groups. For cannabis-only users, young drivers aged 20–29 years dominated during the whole period, whereas for multidrug–cannabis users the median age increased steadily during 2000–2015. After 2009, the annual increase in THC findings escalated; THC-only findings increased the most.Conclusions: Increasing numbers of THC-positive drivers were found among all age groups and genders; the strongest trend was observed between 2009–2015 for young drivers testing positive only for THC.

Overcoming the Plateau: Reducing Impaired Driving by Addressing Drug-Impaired Drivers

The United States continues to suffer from a significant impaired driving problem, in no small part because policymakers and practitioners have focused almost entirely on only one cause of impaired driving: alcohol misuse. During the almost four decades since Candace Lightner founded Mothers Against Drunk Driving (MADD) in 1980, the nation has invested tremendous resources designed to change social norms about drinking and driving and buttressing the identification, apprehension, prosecution, punishment, and rehabilitation of drunk drivers. Consequently, the prevalence of drinking drivers and alcohol-impaired drivers has plunged since the 1970’s.

The effects of drug and alcohol consumption on driver injury severities in single-vehicle crashes

ABSTRACTObjective: It is well known that alcohol and drugs influence driving behavior by affecting the central nervous system, awareness, vision, and perception/reaction times, but the resulting effect on driver injuries in car crashes is not fully understood. The purpose of this study was to identify factors affecting the injury severities of unimpaired, alcohol-impaired, and drug-impaired drivers.Method: The current article applies a random parameters logit model to study the differences in injury severities among unimpaired, alcohol-impaired, and drug-impaired drivers. Using data from single-vehicle crashes in Cook County, Illinois, over a 9-year period from January 1, 2004, to December 31, 2012, separate models for unimpaired, alcohol-impaired, and drug-impaired drivers were estimated. A wide range of variables potentially affecting driver injury severity was considered, including roadway and environmental conditions, driver attributes, time and location of the crash, and crash-specific factors.Results: The estimation results show significant differences in the determinants of driver injury severities across groups of unimpaired, alcohol-impaired, and drug-impaired drivers. The findings also show that unimpaired drivers are understandably more responsive to variations in lighting, adverse weather, and road conditions, but these drivers also tend to have much more heterogeneity in their behavioral responses to these conditions, relative to impaired drivers. In addition, age and gender were found to be important determinants of injury severity, but the effects varied significantly across all drivers, particularly among alcohol-impaired drivers.Conclusions: The model estimation results show that statistically significant differences exist in driver injury severities among the unimpaired, alcohol-impaired, and drug-impaired driver groups considered. Specifically, we find that unimpaired drivers tend to have more heterogeneity in their injury outcomes in the presence potentially adverse weather and road surface conditions. This makes sense because one would expect unimpaired drivers to apply their full knowledge/judgment range to deal with these conditions, and the variability of this range across the driver population (with different driving experiences, etc.) should be great. In contrast, we find, for the most part, that alcohol-impaired and drug-impaired drivers have far less heterogeneity in the factors that affect injury severity, suggesting an equalizing effect resulting from the decision-impairing substance.

Non-prescribed use of psychoactive prescription drugs among drug-impaired drivers in Sweden

AimsTo determine the prevalence of non-prescribed drug use among subjects suspected of drug-impaired driving with a psychoactive prescription drug, and to identify associated factors. MethodsSubjects investigated for drug-impaired driving in Sweden during 2006–2009 with a confirmed intake of diazepam, flunitrazepam, tramadol, zolpidem or zopiclone were identified using the Swedish Forensic Toxicology Database. Information on dispensed prescription drugs was retrieved from the Swedish Prescribed Drug Register. Non-prescribed use was our outcome, defined as a psychoactive prescription drug intake confirmed by toxicological analysis in a subject by whom it was not dispensed in the 12 months preceding the sampling. Prevalence proportions were calculated for each drug and logistic regression was used to identify associated factors. ResultsIn total, 2225 subjects were included. The median age (range) was 34 (15–80) years and 1864 (83.8%) subjects were male. Non-prescribed use was found in 1513 subjects (58.7%); for flunitrazepam 103 (76.3%), diazepam 1098 (74.1%), tramadol 192 (40.3%), zopiclone 60 (29.7%), and zolpidem 60 (21.2%) subjects, respectively. Younger age and multiple-substance use were associated with non-prescribed use, whereas ongoing treatment with other psychoactive drugs was negatively associated with non-prescribed use. ConclusionsNon-prescribed use of psychoactive prescription drugs was common in subjects suspected of drug-impaired driving and was more frequent for benzodiazepines and tramadol compared to zolpidem and zopiclone. The young and multi-substance users were more likely, whereas subjects with ongoing prescribed treatment with other psychoactive drugs were less likely, to use non-prescribed drugs.

The Standardized Field Sobriety Tests (SFST) and measures of cognitive functioning

ObjectiveThe Standardized Field Sobriety Tests (SFST) are utilised widely to assess fitness to drive when law enforcement suspects a driver's ability to drive is impaired, whether by drugs or alcohol. The SFST ostensibly achieve this through assessment of the level of drivers’ cognitive and psychomotor impairment, although no studies have explicitly assessed the relatedness of cognitive ability and performance on the SFST. The current study aimed to assess the relationship between the three components of the SFST with a well validated computerised cognitive battery. MethodA sub-set of 61 placebo condition participants comprised the sample, with 33 females and 28 males (mean age 25.45 years). Correlations between the individual SFST subscales ‘Horizontal Gaze Nystagmus’ (HGN), the ‘One Leg Stand’ (OLS) and the ‘Walk and Turn’ test (WAT) and Cognitive Drug Research (CDR) sub-scales of ‘Quality of Working Memory’, ‘Power of Attention’ and ‘Continuity of Attention’ were analysed using point-biserial correlation. ResultsSixty participants were included for analyses. A weak–moderate positive (five subscales) and a moderate–strong negative (two subscales) association was noted between seven of the nine individual CDR subscales and the SFST subscale of the WAT test (all p<0.05). Individually, a moderate positive association was noted between the sub-scale ‘Nystagmus lack of smooth pursuit’ and ‘digit vigilance reaction time’ and ‘choice reaction time; reaction time’ (both p<0.05) and ‘Nystagmus head move and/or jerk’ and ‘simple reaction time’ (p<0.001). When assessed as a partially composite factor, a comparable association was also noted between the composite score of the SFST subscale ‘Nystagmus head move and/or jerk’ and both (a) simple and (b) digit vigilance reaction time (both p<0.05). No association was noted between any of the individual cognitive variables and the SFST subscale ‘OLS’, or between composite cognitive scores ‘Quality of Working Memory’, ‘Power of Attention’ and ‘Continuity of Attention’ and total SFST scores. DiscussionVariation in some aspects of cognitive performance was found to be moderately and positively correlated with some individual aspects of the SFST; particularly among tasks which assess reaction time. Impairment of these cognitive processes can also contribute to the completion of complex tasks such as driving or the SFST. Complex behavioural tasks such as driving are often severely impaired due to intoxication, and thus in a practical sense, the SFST can still be considered a useful screening tool to identify drug or alcohol impaired drivers.

Cannabinoid disposition in oral fluid after controlled vaporizer administration with and without alcohol

Oral fluid (OF) is an advantageous matrix for cannabis detection, with on-site tests available for roadside drug-impaired driver screening. Limited data exist for device performance following consumption of vaporized cannabis, which reduces exposure to harmful combustion by-products. We assessed cannabinoid OF disposition, with and without alcohol, and evaluated on-site Drager® DrugTest 5000 performance (Drager) following controlled vaporization of cannabis. Forty-three cannabis smokers (≥1×/3 months, ≤3 days/week) reported 10–16 h prior to dosing, and drank placebo or low-dose alcohol [target ~0.065 % peak breath-alcohol concentration (BrAC)] 10 min prior to inhaling 500 mg of placebo, low-dose [2.9 % ∆9-tetrahydrocannabinol (THC)], or high-dose (6.7 % THC) vaporized cannabis (within-subjects; six possible alcohol–cannabis combinations; 19 completers). BrAC readings and OF (Quantisal™, Drager) were collected before and up to 8.3 h post-dose. Median [range] maximum OF concentrations (C max) for low and high doses (no alcohol, N = 19) were 848 [32.1–18,230] and 764 [25.1–23,680] µg/l THC; 6.0 [0–100] and 26.8 [1.0–1106] µg/l cannabidiol; 54.4 [1.8–941] and 29.7 [0–766] µg/l cannabinol; and 24.1 [0–686] and 18.0 [0–414] ng/l 11-nor-9-carboxy-THC (THCCOOH). Lack of significant differences in THC concentration between low doses and high doses indicated that participants may have titrated doses. THC, cannabidiol and cannabinol C max values were immediately post-inhalation, but metabolite THCCOOH t max showed interindividual variability. Concurrent alcohol did not affect OF cannabinoid concentrations or on-site test sensitivity. With a THC confirmation cutoff of 5 µg/l, Drager sensitivity, specificity, and efficiency were 60.8, 98.2, and 82.5 %. Drager had lower sensitivity after 6.7 % THC vaporization (53.8 %, THC ≥2 µg/l confirmation cutoff) than reported following smoking a 6.8 % THC cigarette, but high specificity (99.3 %) and comparable efficiency (65.0 %). Vaporized THC bioavailability may be lower than that when smoked. Confirmation cutoff, time course, intake histories, and additional cannabinoid analytes also affect OF interpretation.

Drinking and parenting practices as predictors of impaired driving behaviors among U.S. adolescents.

The purpose of this study was to identify the extent to which 10th-grade substance use and parenting practices predicted 11th-grade teenage driving while alcohol-/other drug-impaired (DWI) and riding with alcohol-/other drug-impaired drivers (RWI). The data were from Waves 1 and 2 of the NEXT Generation study, with longitudinal assessment of a nationally representative sample of 10th graders starting in 2009-2010. Multivariate logistic regression analysis was used to examine the prospective associations between proposed predictors (heavy episodic drinking, illicit drug use, parental monitoring knowledge and control) in Wave 1 and DWI/RWI. Heavy episodic drinking at Wave 1 predicted Wave 2 DWI (odds ratio [OR] = 3.73, p < .001) and RWI (OR = 3.92, p < .001) after controlling for parenting practices and selected covariates. Father's monitoring knowledge predicted lower DWI prevalence at Wave 2 when controlling for covariates and teenage substance use (OR = 0.66, p < .001). In contrast, mother's monitoring knowledge predicted lower RWI prevalence at Wave 2 when controlling for covariates only (OR = 0.67, p < .05), but the effect was reduced to nonsignificance when controlling for teen substance use. Heavy episodic drinking predicted DWI and RWI. In addition, parental monitoring knowledge, particularly by fathers, was protective against DWI, independent of the effect of substance use. This suggests that the enhancement of parenting practices could potentially discourage adolescent DWI. The findings suggest that the parenting practices of fathers and mothers may have differential effects on adolescent impaired-driving behaviors.

Canada's New Drug-Impaired Driving Law: The Need to Consider Other Approaches

Objective: The objects of this study were: To review the state of drug-impaired driving in Canada, particularly in light of the 2008 amendments to the Criminal Code, which authorized police to demand standardized field sobriety testing and drug recognition evaluations, and to consider whether alternative enforcement models would be more effective in terms of detecting and prosecuting drug-impaired drivers and thereby achieve greater deterrence.Method: This article provides a review of survey data, roadside screening studies, and postmortem reports that indicate the prevalence of driving after drug use in Canada. It evaluates the Criminal Code's 2008 amendments and their impact on charges and convictions for drug-impaired driving. It then reviews some alternative enforcement models for drug-impaired driving that have been adopted in other jurisdictions, particularly toxicological testing, and evaluates them against Canada's social, political, and constitutional framework.Results: Survey data, roadside screening studies, and postmortem reports indicate that driving after drug use is commonplace and is now more prevalent among young people than driving after drinking. Unfortunately, the 2008 Criminal Code amendments have not had their desired effects. The measures have proven to be costly, time-consuming, and cumbersome, and are readily susceptible to challenge in the courts. Accordingly, the charge rates for drug-impaired driving remain extremely low, and the law has had minimal deterrent effects.The review of alternative enforcement models suggests that a system of random roadside saliva screening, somewhat similar to the model used in Victoria, Australia, will be the most effective in terms of detecting and prosecuting drug-impaired drivers and most consistent with Canada's legal and constitutional system.Conclusions: Canada should establish per se limits for the most commonly used drugs, enforceable through a system of screening and evidentiary tests. This will be more efficient and cost-effective and will result in more reliable evidence for criminal trials. Although this system will inevitably be subject to constitutional challenge, existing case law suggests that it should be upheld as a reasonable limit on constitutional rights.

Results of the Queensland 2007–2012 roadside drug testing program: The prevalence of three illicit drugs

The purpose of this investigation is to present an overview of roadside drug driving enforcement and detections in Queensland, Australia since the introduction of oral fluid screening. Drug driving is a problematic issue for road safety and investigations of the prevalence and impact of drug driving suggest that, in particular, the use of illicit drugs may increase a driver's involvement in a road crash when compared to a driver who is drug free. In response to the potential increased crash involvement of drug impaired drivers, Australian police agencies have adopted the use of oral fluid analysis to detect the presence of illicit drugs in drivers. This paper describes the results of roadside drug testing for over 80,000 drivers in Queensland, Australia, from December 2007 to June 2012. It provides unique data on the prevalence of methamphetamine, cannabis and ecstasy in the screened population for the period. When prevalence rates are examined over time, drug driving detection rates have almost doubled from around 2.0% at the introduction of roadside testing operations to just under 4.0% in the latter years. The most common drug type detected was methamphetamine (40.8%) followed by cannabis (29.8%) and methamphetamine/cannabis combination (22.5%). By comparison, the rate of ecstasy detection was very low (1.7%). The data revealed a number of regional, age and gender patterns and variations of drug driving across the state. Younger drivers were more likely to test positive for cannabis whilst older drivers were more likely to test positive for methamphetamine. The overall characteristics of drivers who tested positive to the presence of at least one of the target illicit drugs are they are likely to be male, aged 30–39 years, be driving a car on Friday, Saturday or Sunday between 6:00 pm and 6:00 am and to test positive for methamphetamine.

An Examination of the Validity of the Standardized Field Sobriety Test in Detecting Drug Impairment Using Data from the Drug Evaluation and Classification Program

Objective: The purpose of this study is to assess the validity of the 3 components of the Standardized Field Sobriety Test (SFST), including the Horizontal Gaze Nystagmus (HGN), One Leg Stand (OLS), and Walk and Turn (WAT) tests, in identifying impairment among suspected drug-impaired drivers using data recorded during drug evaluation and classification (DEC) evaluations. Methods: Data from 2142 completed DEC evaluations of central nervous system (CNS) stimulants, CNS depressants, narcotic analgesics, cannabis, or no drugs were analyzed using multinomial logistic regression. Results: All drug categories were significantly associated with impaired performance. On the HGN, users of CNS depressants were significantly more likely to experience lack of smooth pursuit and distinct nystagmus at maximum deviation compared to non-drug users. On the OLS, users of all drug classes were significantly more likely to sway while balancing and use their arms to maintain balance but significantly less likely to hop compared to drug-free cases. Users of CNS depressants, CNS stimulants, and narcotic analgesics were significantly more likely to put their raised foot down during the test. On the WAT, users of CNS depressants, CNS stimulants, and narcotic analgesics were significantly less likely to keep their balance while listening to test instructions compared to those who had not used drugs. Users of CNS depressants were less likely to touch heel-to-toe while walking, whereas individuals who had used narcotic analgesics were less likely to take the correct number of steps. Conclusions: These findings provide support for the use of the SFST as a screening tool for law enforcement to identify impairment in persons who have used CNS stimulants, CNS depressants, cannabis, or narcotic analgesics.